...a family members child. It went from working on a relationship and moving in together to. Hey! I'm gonna be a single mom with a nine month old. Should I even stay if I'm not sure or ride it out?
Riding it out could potentially be a very long time, if she has a foster child now, that could stay with her for years. You need to evaluate how much you love her and if you can handle the situation. Talk to her about it and about your concerns. Communication is important.