10 year old girls are not really supposed to be wearing any kind of cup size.It's best to wear training Bras or sports bras...But if a 10 year old were to wear a cup size it would probably be a 32AA...11,12 and further that's when you really start to wear a cup size.
A 10 year old girl would likely wear a size 10 to 12. This is just average though, some will wear bigger and some will wear smaller.
size 12 or 14
An average would be about 7-8 or 8-9
Should wear 7/8 or meduim
Usually she would wear age 6-7 or 7-8 sized clothes, but depending on her weight and height, the size could vary dramatically.
my 3 year old Jenny wears size 9 but most of her friends wears size 11 or 12.
A 12-year old girl should wear a size 12/14. If the girl is tall, she may want to go up a size so things will fit better.
A 4 or if she was little a 2t and possible a 5 or 6
If you've hit puberty then you dont really have a size until you are like 16 then the average size is 34d. So u should b close to that i guess I am 13 & i wear a 32c, but all my friends wear either 32a or 32aa, so i have big boobs compared to all of them!