S., could be her hormones, but really maybe the fact that her "dad" is in Iraq makes her worry and that is the only way she knows how to express her feelings. Take her to a counselor,let her express herself there, this could be her way of asking for help. Also if it is her hormones, get her active, let her play sports, swim, basketball, whatever is going on right now,this can help with her body image, and the more active you are the less likely you are too start your period early. Also what about Karate, this teaches self respect, respect towards others and it will keep her physically fit.
Keep your head up, I too have a loved one in Iraq and you know that everyday you worry, so think about what she is going through, take how you feel about him being gone and triple it for a 10 year old, she doesn't (more than likely) understand why he is gone for so long. Be there for her, love her and let her know that no matter what you are there for her unconditionally.