if she has started her period or has not and it is normal
for females in
your family to have started it by now, you might want to have her checked for PCOS. especially if she does not eat alot but seems to gain easily. testosterone, fsh, lh, estrogen, progesterone. girls are having symptoms of PCOS younger and younger. granted this may not be her problem, but like i said, if she gains easily and is not eating/sneaking a lot of food/drink it could be worth checking into.