She's using you. Her life is upside down right now, and she's looking for a little stability. She's using you as a stepping stone until she decides what to do next. There's no way she's ready to be in a new relationship, with all the issues in her life.
The first thing you need to do is separate your finances. What if she takes off with all the money in the joint account? Legally you wouldn't have a leg to stand on in trying to get it back. You say "so far she has been trustworthy with money." It sounds like you suspect that at some point she won't be. Why have that stress hanging over your head?
The next thing to do would be to give her a date by which she has to leave. Without you to depend on, she'll be forced to take charge of her life and decide what she really wants to do.
From what you've said, she sounds like she has some major co-dependency issues. What does she mean that she "doesn't know how" to get a divorce? How about speaking to a lawyer?
She's not ready for a new relationship. And it sounds like you're inviting too much unneccessary drama into your life with this one.