Awesome choices. My son is a Firstie at West Point, and when I ask if he would have gone to either usna or usafa (had appointment to both), he says no, but might have done CGA. A coast guard career would be very cool.
My two cents would be that a 17-18 year old kid has absolutely no way of knowing if he/she would "prefer a career" in any branch over another, and probably can't predict at that age whether or not a military career is the best option at all. Go with what feels best for whatever the reason right now, and hope it works out.
I will say that, while the education itself is probably pretty equal at all of the academies, a degree from West Point will always carry that historical prestige, and that is worth as much or more than any Ivy League school for sure. So the civilian career element may favor USMA, but still, have her decide based on what feels best in her heart. Both are fantastic.
...Me? I'd rather be in the CG than the Army. Just saying.
But, Go Army! Beat Navy!