I have only read the first and last pages of this thread, so sorry if I am off base in my comment.

You mentioned she is in nursing school. I am in my late 30's and graduated from nursing school over a year ago. I am trying to understand how she has time for nursing school, which is literally like a full-time job (and then some) on it's own, kids, did you say she works? as well as all of the hanging out she does. I only worked part-time while in school, have no kids, am not married, and I didn't have time to get enough sleep let alone time to go out with friends--and those friends were my classmates!

Anyway. I probably don't have anything super helpful to say. I do feel like, if I were married and back in school, the LAST thing I would want to do is go through a divorce on top of it all, especially if it would screw with a) child care--huge b) my time c) my financial status d) my student loan status (though she gets more aid as a single parent). Essentially, I wouldn't want anything to mess with the status quo. I have no idea what she's thinking, but it seems reasonable. I agree with everyone else, take care of you. I feel like you're not going to get anywhere trying to hash it out with her.