At the end of the day, you're lass might seem a bit broken and like a "fixer uppa" project at the moment but underneath there somewhere is someone just looking for the same thing that you are. Companionship. Someone to talk to and share things with. If it develops further than that then I can pretty much guarantee that the effort that you put in will come back to you in spades! And if it doesn't go any further, sure you've lost some time but you've improved someones life. Bloody unselfish thing to do in a pretty selfish world.
My best mate and his wife have just had their first child. They have also just started their own new business. It's proving to be a lot of financial strain and that in turn has manifested itself into strain on their relationship. He has developed full blown depression, anxiety and a massive lack of trust. He's suspicious of everyone. Thinks that everyone is either judging him, stealing from him or attempting to undermine his relationship. The crazy thing is, the only one that's undermining his relationship is himself. As much as I can I'm helping out. Fortunately, I knew the guy before things went south so I know the bloke that people see and meet nowadays is definitely not who he really is.
I guess what I'm trying to get at is that if it's worth it, you'll know. And clearly she is. Just like I know my mate is. You wouldn't be here expressing your concerns etc to a bunch of strangers if you didn't feel she was. So take pride in what you're doing, small steps at a time, treat every little win as a major milestone and regardless of what happens, don't throw in the towel just cos it gets hard!
Massive respect to you also by the way for being so candid. It's refreshing to see someone speak so freely about something that is certainly not a minor issue. Kudos bro.