When Do Girls Enter Puberty?

Updated on May 23, 2013
G.♣. asks from Springfield, IL
28 answers

My MIL is concerned about my niece. (Now, my mother is concerned about everything and doesn't usually know how to bite her toungue, so I take this with a grain of salt.)

My niece just turned 13 and hasn't started her period yet. I've learned that "puberty" means different things to different people. Some think of physical changes - curves, boobs, etc. - while others think of starting your period.

Just curious, but is 13 really that late to start your period? I was about 12, so I figured 13 was perfectly accetable. My MIL said she was 10, so she thinks 13 is cause for concern.

For what it's worth, I have 2 boys, so I really have not given this much thought.

What can I do next?

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So What Happened?

It is so refreshing to hear so many people say that my MIL should mine her own business. I could not agree more!!!

My husband's sister and her family live with my MIL and FIL - for now. They will be moving out soon. We're kind of the black sheep of the family, as we live 2 hours away and don't share every detail of our lives :-)

I was pretty sure there was nothing to worry about, but curiosity got the better of me.

Thanks for all the responses!!!

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answers from Dover on

I agree with the others, normal is a very broad range. Typically, puberty is coming earlier than it used to but 13 is still normal. Additionally, I understand that many times girls that are very athletic may be even later than that.

I also agree what MIL needs to mind her own business and stop discussing personal details with the family. I have a relative like that and that is why I share nothing I don't want repeated. How does MIL know that she hasn't started her period yet? If mom or dad is sharing, they need to STOP IT NOW!

6 moms found this helpful


answers from St. Louis on

I was 13, my oldest 13, my younger daughter is 12 and hasn't started and I am not to fussed about it.

2 moms found this helpful


answers from New York on

Some girls start as early as age 8, others not until 15. There are many factors to consider. It's best to discuss with the child's doctor.

1 mom found this helpful

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answers from New York on

Menarche (onset of menstruation) at 13 or 14 is perfectly normal and healthy.

I do think there's a source of concern, though, and that's that your MIL (or mom? or both?) has serious boundary issues and is subjecting this poor preteen girl to terrible humiliation by bringing up the nitty gritty of her bodily development to every relative in the book. You, as her loving auntie, really shouldn't know whether this poor girl has started her period or not.

Are you -- or anyone -- in a position to sit grandma down and introduce her to the brand spankin' new concept of privacy?

12 moms found this helpful


answers from Los Angeles on

A girl starts her period for a variety of reasons.

I know I'm and man and don't know anything about periods except the ones at the end of sentences.

But I love the Olympics. May Lou Retton was being interviewed on the Today program after winning all her medals in the Olympics. One of the questions she was asked was about what changes had she experienced in her life since the Olympics were over and she was officially retired. She said, "Well, I just had my first period and now I'm growing boobs." The hostess turned beet red, looked down and covered her face with her hand. Mary Lou said, "Well, I was always in training and my body fat percentage was so low I never had enough body fat to have a period or to have boobs." I laughed and laughed. So did the audience.

That having been said, Why does anyone know about it but the mom and her daughter? I didn't know about my own daughters starting until my wife bought a different kind of feminine product and I asked why.

Good luck to you and yours.

8 moms found this helpful


answers from Salt Lake City on

The range for normal is pretty wide. Growing up, I remember the youngest of my gaggle of girlfriends was 9, and the last in the bunch was 14. None of us were considered abnormally early or late.

Why is this any of your MIL's business? I'd consider her intrusion to be a much bigger problem than your niece's lack of a period. If the child's mother and doctor aren't worried, then MIL needs to butt out. In your niece's place, I'd be absolutely mortified to learn that my period or lack of one was a topic of family discussion!

6 moms found this helpful


answers from Columbus on

First of all, you should tell your MIL everyone is different. I was 14; my daughter was 13.

Additionally, my daughter would have killed me if she knew my MIL knew anything about personal stuff like this!! I would just tell her to not worry about it; when it happens, it happens!!

Good luck!!

5 moms found this helpful


answers from Honolulu on

Puberty doesn't mean, only getting your period.
It is also not MIL's business.
This is personal info, for your daughter.
Oh sorry, this is your Niece.
Well, gosh, this would be a personal matter between her and her Mom.
Its private info.

MIL has to realize, that not everyone is like her.
10 is early.

Why does it even matter, when your Niece gets her period or not?
I feel sorry for your Niece and her Mom. I mean, this is their own personal lives and everyone is talking about them and the Niece's period.

Puberty means, the hormones changes and the hair growth and body odor and the development of boobs as well.
And their cognitive and emotional development too.

My daughter is 10. And I would never... tell others about her own personal bodily changes or development or when she has her period or not.
And, if all the relatives in my family were discussing my daughter's body shape or curves or boob development or when she is getting her period... I would tell them It is NONE of your business.

5 moms found this helpful


answers from St. Louis on

Why is your mother in law even involved in your niece's period timing?!

13 is perfectly acceptable. In fact, doctors see more problems with those who start earlier rather than later. The inordinate amount of consumption of hormones and other chemicals and a plethora of other issues are causing girls to develop far earlier than they should. So perhaps your niece is more healthy than her peers as well.

MIL needs to find a hobby. Let me guess, she is retired.....

5 moms found this helpful


answers from Tampa on

Your MIL REALLY needs to learn some boundaries. This is NONE of her business and she is showing REALLY bad form talking to everyone about this. I can totally see my MIL doing something like this. She thinks that because someone is family, that their entire life should be on display.

FWIW, I didn't start mine until after I turned 15 and I never remember my Mom having any heartburn over it. I suspect that my daughter will be the same way.

4 moms found this helpful


answers from San Francisco on

I started at 14, as did my oldest daughter.
My younger daughter is turning 14 next week so I expect it will happen soon!
She is later than most of her friends, most of whom started around 12/13.

3 moms found this helpful


answers from Detroit on

I was 13 when I first started my period, and I am perfectly healthy, so I am not sure why your MIL would be concerned about what she perceives as late-onset puberty - I mean, whether it happens at 10 or at 14, does it really matter? Besides, puberty is a process - it's physical changes, sure, but it's also emotional. Some girls will start get to breast buds or pubic hair or body odor way before they actually start menstruating, and it's different for everyone. Maybe your niece's mother should remind MIL of this and to tell MIL not to worry and to mind her own business?

2 moms found this helpful


answers from Columbia on

I was nearly 15. Every girl is different.

2 moms found this helpful


answers from Baton Rouge on

I didn't start until I was 17. My daughter started when she was 9.

1 mom found this helpful


answers from Norfolk on

If it runs late in your family, I wouldn't worry.
It use to be 12 through 14 (or later sometimes 16) in my mothers generation.
I was 11 when I got my period.
And now some girls start sometimes as early as 7 through 9.
My Mom's generation was starved - Great Depression meant many people were on the brink of starvation.
We were better fed.
And right now there's an obesity epidemic - and the heavier you are, the sooner the period starts.
Your niece is fine and your MIL should relax.

If MIL can't seem to mind her own business then every time she brings up anyone else's periods, you should start pressing her for details about her menopause.

1 mom found this helpful


answers from Washington DC on

My pediatrician told me that when they reach 100 lbs is about when it all falls into place.

1 mom found this helpful


answers from San Francisco on

No, I was at least 13 or more, so unless she is unusually skinny, there's no cause for concern.

1 mom found this helpful


answers from Augusta on

13 is perfectly acceptable.
Daughters usually start their period around the same time their mother started.
now as for Puberty starting that's when the hormonal /physical changes start. Average is 9-12 I believe.

1 mom found this helpful


answers from Washington DC on

My daughter started around 9....

It's different for everyone. I didn't start my period until I was 13. My daughter - 12.

If she is athletic or in gymnastics? She might have it later. but really - what is it to your Mother in law? I realize she's her granddaughter - but really? Is it something you announce to the world when your daughter starts her period? Man. I think I would have been embarrassed about that!!

It will happen when it happens. If she doesn't have it by 15 or 16 - yeah - I might worry. But again - if she's athletic - that can play a role in when she gets her period.

Puberty for me? Means the hormones, hair in the armpits and groin area as well as "smell" for both boys and girls - for girls - all that plus breasts and period.

Good luck!

1 mom found this helpful


answers from Rockford on

Poor girl is going to start to think something is wrong with her for being completely normal.
I started mine when I was 14. My mother started when she was 16. My Grandmother when she was 10. It really varies by person.


answers from Los Angeles on

Is your niece particularly active in sports and very athletic? I do know that being athletic and low body fat delays the onset of starting her period.



answers from Chicago on

Puberty hits at all ages. I was 14 and my sister was 16. My cousins were as young as 9. So it depends on the individual. As a girl, I was glad I was a late bloomer, it was great for sports. You have all your life with the inconvenience of having a period, I wouldn't worry.



answers from Chicago on

I was 15 and my sister was 9 - same parents



answers from Dallas on

She is worrying over nothing. At 13, it isn't a big deal if she hasn't started her period yet. If she was 16, then I might think of consulting a doctor. Everyone is different. I started when I was about 12, my daughter was 10. I have a friend that was almost 16 when she started.



answers from Chicago on

I was 17 and all the other women in my family were about 12 or 13. The dr. said it wasn't concerning until I was 18 and then they would start doing more invasive testing. She is fine.



answers from Chicago on

16 is cause for looking into it, 18 is cause for concern according to my daughter's doc
Now my kids are VERY skinny, so that may be something to factor in, the skinnier you are the later you start



answers from Columbus on

I was 10, which is now considered super early - it's just the genetics of my family (not hormones in meat). Some girls are 15 or 16. There is a large range of normal. 13 is perfectly fine.



answers from Wausau on

I was 14. Most of my friends were 13 or 14 too. The first girl in my graduating class to get hers was barely 10. It was really hard on her. The latest that I know of was two months shy of 16.

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