In the eyes of God, can I date/marry a non-divorced woman if her husband deserts her?

[Let me say sorry this is so long but i feel its all necessary] I have been in a relationship for about three years now with a young lady with a now three year old, and i have let my moral compass go haywire to make thins work. Now, i see the need to get right with God, but i don't know if i can be with them and still be pleasing in God's sight. I really care for them, and don't want to hurt them, but i REALLY feel the need to get right with God, even if that means i have to leave them in order to pursue righteousness. I want to pray and seek God for an answer, but I recently learned that until i remove sin (especially known sin) from my life, God will not hear me when i pray. So i have told her that i intend to do what i feel will allow me to seek God with my whole heart, even if I must leave them to do so - she never really responds to my words though. In fact, i think she may be mad at the fact that i want to turn over a new more righteous in God leaf and that I'm asking her to make these changes with me in order to be together with me. I keep telling her that there's no love lost over this but that i still care about them and really want this to work out for us to be together still, but for some reason she keeps insisting that i just dont love her and that she's not good enough and that basically she is a victim in all this - when all she has to do is agree to be open to this new direction in life or admit that she doesnt wanna do the things needed to still be together under God. In either case, i'm conflicted because it looks as though i may be waivering in my resolve, especially as she is trying to manipulate me into staying with her and staying more or less the same - when im telling her that there are things we've entertained in the duration of our relationship that in God's eyes are sinful and displeasing to him and that for "us" to work she also must be 100% willing to give up these things and habits as well, to walk with me and not resist for comfort etc. I know she may be scared, but she wont admit it if she is, shes very distant on the issue and very non-responsive, non-sharing of how she really feels and what she really thinks, and just acting like im treating her badly when im trying to tell her to walk with me or let me go. I know its long reading, sorry. Thanks for any help.