if she has already had the shot, all you can do is wait it out really. however, with her history of depression and suicide attempts, depo should have been contraindicated. that said, they probably chose it because she is so young, and remembering a pill everyday can be hard at times and because of her BMI they have to watch the dosage no matter what they put her on. its probably best that she try to take as good care of herself as she can and at the end of the three months, if she wants, discuss a different form of bc with her doctor.