Halloween - Fort Stewart,GA

Lois Lane! Long sleeved white sweater or onesie, depending on how warm it is, black tights/leggings and a black skirt, and make her a "Press Pass" that says Lois Lane and The Daily Planet. You can get a name tag on a magnet from Office Max, pull the Daily Planet logo off the internet, make up a little name badge and you can stick it to her top without worrying about pins or something around her neck. Maybe a cute hair bow with Superman logos on it to top it off :)

Make it something functional, that feels like clothing to her. No 9 month old wants to feel constricted by something they can't understand. I saw a really cute costume last year, where the mother got an orange onesie (or shirt, I don't remember) and put a pumpkin face with black fabric on it. She then made a black and orange tutu and she wore black and orange leggings. It was adorable, and baby seemed very comfortable. I would go the direction of Halloween themed, rather then all out costume. I don't think it's fair to stick an infant in a costume.

A lump of Kryptonite - just dress her all in green :)

If you're going to be carrying her what about a baked potato? Use a tan receiving blanket and then add something white. Wrap the whole blanket and white with some foil. Sprinkle some green pieces for chives.

Arrange the baby in the carried seat and make sure all the pieces are showing so it's obvious what she is.

1) Keep in mind what the weather and temperatures are in October, in your area.
2) then, based on that, think of a "costume."
3) For me, I would make a "costume" using a onesie. That will be most comfortable for a baby.
4) Using felt, is very versatile. Because, after you cut it into whatever shape, you do NOT have to sew up the edges because, it does not fray. And, felt can be... glued or simply hand-stitched onto her onesie. If using glue with the felt, use hot-glue or fabric glue. And felt can be found in many colors and from a craft store. And is not expensive.
5) make sure, that the underside of her onesie, does not have anything "pokey" or rough or anything (like if you sew stuff onto the onesie, the stitching may bother her under the onesie. Babies have sensitive skin).

We made our son a Burrito for his first Halloween. It was fun and easy, we even included tin foil wrapping! A friend made a bunting that was a tortilla, and around his shoulder area was a piece that resembled lettuce, tomato, cheese, and beans, with tin foil around the bottom, it worked out great, especially since he was being held as we gave the kids candy.

We ALWAYS did costumes based on something baggy that could take a sweatshirt, leggings, or a coat underneath. Obviously, with a 9 month old, this costume is just for fun and photos, nothing for her. I'd go to the consignment or children's resale shop and see what's there.

You can always take a black or yellow sweatshirt and pants, and get some felt from the craft store in the opposite color, make stripes: instant bee. Orange and black: instant tiger. Add some drawn-on whiskers with eyebrow pencil or halloween make-up that's non-toxic. Or a green set of sweats, add a stretchy hat, and split a styrofoam ball or a ping pong ball, mark with a black sharpie, and glue on: instant frog. Those work if she's being carried or being put in a stroller. SH is right about felt being so easy to work with, no frayed edges, lots of room for mistakes!

If this is for an indoor party and not door-to-door trick or treat, go for tights and a onesie or a turtleneck if you can stand putting them on her!

The costumes with wings or a tail are harder if she's in a stroller.

Keep in mind that anything you put on her head, she's likely to try to take off, so I wouldn't go for headband-style boppers unless they only cost $1 and aren't critical to the entire costume.

For the future with your 3 year old - we've seen some great homemade costumes with boxes that can be worn over sweats or even heavy coats: cut holes for head and arms and go from there. 1) Attach a bunch of white balloons and label the box "SOAP"; 2) attach a bunch of rubber or plastic knobs (an old TV remote, the caps for the bottoms of chair legs, etc.) and you have a robot. Add pieces of flexible dryer hose for the arms, attach a cup hook and hang the candy bag on the box itself. 3) There was one painted blue with postal service logo, with a movable flap in the front - the kid was a public mailbox! There was a box or bag inside to catch the candy deposited. It was awesome!

An angel. Very simple to make.

What about wonder woman or bat girl....some type of girl super hero would be cute.

Ice cream cone (she's the scoop, cone hat).

Cloud (wear a white fluffy outfit).

My daughter was 10.5 months for her first halloween. She was a witch. My aunt had found a very pretty orange and black witches dress with black hat on sale BEFORE my daughter was even born). We put a black long-sleeved onesie and black pants under it for warmth and comfort. I went to the dollar store and found a little "black cat" bag for her to trick or treat with.

I loved the jack-o-lantern (orange onesie) idea below. Or something similiar using a super hero theme to go w/ your son (maybe dress her normal and call her Lois Lane).

A few easy things I made for my kids' early costumes began with a blanket sleeper.
I made the Cheshire Cat. Found a hot pink sleeper then bought the spray on fabric paint and put the purple stripes on it. I used the blue painters tape to mark them out. I then bought some hot pink polar fleece and made a tail that could be sat on, sewing it at the tail bone area on to the sleeper. We were driving somewhere so it had to be OK in the carseat. I then had a headband with cat ears.
Another year I made a fairy dragon. A light blue blanket sleeper with darker blue ribbing. I bought polar fleece again in a darker blue. I cut an oval for the chest and stomach area. I sewed it to the sleeper on one side of the zipper and used Velcro to attach it on the other side, over the zipper. I got some tulle and used a few layers and gathered them in the middle like a bow and sewed it all together in the middle. I used a small safety pin to attach it to the back. Again, it needed to be worn in a carseat. I had a light blue hat in a similar color I put on them.
My daughter's first Halloween costume we admittedly bought. She was Tinkerbell. I saw it and just had to have it! ;)

Supergirl or a superhero to go along with your son. My kids 9(Boy) & 6(Girl) want to be Minions, so maybe your 9 month old can be that. I'm just doing a yellow hooded sweatshirt and overalls. Sewing the Gru logo on them and adding some hair on top with pipe cleaner and making some goggles or buying some. I make my own costumes too. Last year my son was Link (you know from Zelda) and my daughter was a black cat.

Hey, it's not too early. I already bought about half the supplies I need to make my DD's pirate costume!

I would pick a superhero, and make her a half-tutu version of it (or full, if she is walking yet.) Since they are coming out with a movie that will have Superman and Batman in it, I personally would opt for batman. You can just put her in a black long-sleeved onesie and tights, attach some ears to a black cap, tie strips of tulle to an elastic and cover the waistband with yellow ribbon. :) you could also make a a cape, and use is a blanket if it gets a little chilly.

My MIL has a skunk outfit that she made for her sons Halloween, It is adorable. My son wore it for his second one and I think my daugther who is tiny migth be alble to wear it this year.

Pumpkin
Butterfly
Wonder woman-to go with superman?
Bird
My little pony
Bumble bee

Good luck

Minnie mouse pooh mouse pumpkin