Dear dear VL, Really, You don't have to talk to her. NOT trying to be a shoulder for her to lean on is probably the best idea even She needs to find her own support group outside you and the cop. You can't fix her. You have yer hands full with your self, ya know? Guilt doesn't allow for clear thinking.
Just cause you were involved in her "breaking" doesn't mean you can be involved in her "fixing". Learn all you can from this whole mess, forgive yourself for learning the hard way, and peel yourself away from the patterns you decide don't work for you. Do one new thing to take care of yourself. I think that's what our will is for, to make us do what we know is best... HARD. HARD. HARD. But possible. Be strong, Be the change you want to see in your life. You can do it. One step at a time, noble nibble nibble yer way through.