Bra sizes have nothing to do with waist size. A slim girl can have a large bra size or a small one. It just depends on her DNA.
The biggest bra size that us girls can have so far is 38kkk
Well if your talking bra sizes then... A A34 bra size is what most girls 12 to 13 wear. A B36 bra size is the bra size right after the A cup.
you can get a bra measure from primark
An A or a small B cup cause they are so slim
Your only option is to guess the girl's bra size. If you are not buying her a bra, you don't need to know her bra size. Try to find out something that's important to her instead.
triple z
36A, but every one is different
No, but there are preteen bras that would be in the size of an AAA bra size. It would probably be in the size 12-14 bra.
You can't. All you can do is guess.
what ever size you get or type
There is NOTHING wrong with you, most girls of 12 do NOT wear a regular bra, maybe just a cammisole or training bra!
The average bra size for teenage girls can vary widely, but it is generally around A to C cup sizes. It's important to remember that bra size can change frequently during the teenage years due to growth and development.