Sorry her therapy hasn't been more helpful. It's very possible she needed meds all along to even get any benefit from her therapy or to not take it the suggestive things they say there so literally as to think you are stealing her "voice." I don't know what to say. I'm sorry you are going through this.
I don't know there is any way to help anyone else think anything. It will only come across as pressure. Heavy reliance on a therapist to tell her what to think is another example of a lost "voice." If she's lost, she'll replace her identity with therapy stuff for awhile. If she ever comes out of depression, maybe she will find a voice. But if she's had OCD and chronic depression (unmedicated?) so long, sounds like she'll never find her way. Some therapists don't encourage clients who could benefit from meds to get them either. They like clients who need to come for a year or longer and never get better. Sounds harsh, but it exists. I had a friend in therapy for four years and there was never much wrong with him. His family was just willing and able to pay. Now that he's on prozac, he doesn't need therapy and his worries and thoughts aren't so circular. Hmm...
It could lift on its own in the future and she could realize she divorced someone she loved for no good reason, but I don't see how you can hurry that process up. And if and when that happens, why should you wait? It could just happen again in the future if she does not do very careful self care of meds or if not meds, therapy and a ton of exercise of some sort or whatever it takes. The lifestyle self care stuff some IC's talk about. Sorry not to sound more hopeful at this point.
It seems you have tried. Only you know how she will respond to you emailing that MLC for Dummies thing. Seems like she will tune it out and think, "He wants me to be having an MLC because he's trying to "silence" my "voice" just like the therapist said." It's just a tragic, ridiculous mess. Sorry.