K.S.
I have severe scholosis and know how she feels. If she does not have scholosis (which usually rear's it's head around this time or earlier) then perhapse it is a muscle thing. I would suggest a chiropractor ( a good one is worth their weight in gold). Or even - if you want to make a mommy / daughter thing out of it.... go get a massage! I can't afford them anymore but when I could they were a luxuery well worth the $. She might be very tense and keeps it's all hidden there.
I have not tried this place out but got a mailing for ...
www.academyofaestheticarts.com
They have pretty cheap massages.. If anybody know if they are good or not - I would love a recomendation.