My conversation with my daughter happened very naturally when she was about 9. She said she had a little blood in her underpants so we went to the bathroom. (For some reason, I didn't think it was her period yet.) I told her that we needed to check to see where the blood was coming from so we would know if she had a urinary tract infection or if she was menstruating. She wanted to know what menstruating was, so I explained about their being a little nest called a uterus in her body and that women's bodies release eggs once a month. If the egg is fertilized, it becomes a baby and if it isn't fertilized, her body will wash it away. I had her sit on the toilet and wipe herself up front to see if there was any blood. Then I had her wipe herself back further and told her that that was the vagina and the birth canal and where the egg & blood would come out. Turns out that she did have a UTI, but the conversation was very natural and comfortable. When my husband went to kiss her in bed that night, she was very excited to tell him, "Daddy, I might be getting my period!". Very cute. When my twin boys had asked what the pads were for, I simply said that they were so my underwear wouldn't get stained. They were satisfied with that simple answer. Last year in 5th grade, they had puberty night -- they learned about their own puberty and girl's. Since then, we've had innumerable questions and discussions about the most unimaginable things. I don't think it's necessary to tell them more than they need to know (they're 11), but if they ask, I will answer their questions with a straightforward, truthful but simple answer. (I had to clarify something recently, though. When a woman gets her period because the egg wasn't fertilized, one of the boys thought that the egg passing through was similar to a chicken egg!) I swear I'm going to write a book some day!