Osteoporosis?
Answers: some race are more prone to osteoporosis than others.. but just because you're prone doesn't penny-pinching you are going to get it... consider it a rebel and a warning for you to prevent it from scheduled..
drinking milk (or calcium supplements) will help.. exercising will preserve your bones strong -- exercises that are more physically demanding help make the bone stronger (e.g.running over biking, basketball over swimming)
exposing your self to the sun (early morning sun -- till 9am for about 15 minutes) help .. vit.d and all that ...
amazingly interesting question i don't know the answer though i would assume she's smaller number likely to be effect don't take my word for it.