Hi wbrady11,
I’m sorry that this happened. I would find this tough. It sounds like she has an anxious attachment style, a lot of people do at least 30%, just know that it’s not about you it’s about her attachment style. Try not to take that personally.
You probably don’t want to hear this part and it’s not 100% certain it’s possible that the father of the kids reconciled? A r/s might have several break ups up or dozens before the big one and they actually break up. Maybe she felt anxious and didn’t want to be alone and she wanted soothing.
It’s also possible that she’s anxious and it’s her first child and she just wants space but she did drop out of your life suddenly so you have to look at that pattern.
I don’t think that there’s anything that you can do at the moment the best thing to do is to give her space.