Well Nick, one thing about internet support forums, there's no lack of opinions.
I see that as good thing if it causes you to study the possibilities and explore avenues open to you, thereby allowing you to make the best decisions for you and your family. You have access to the research on the topic and have resources in your home area. I wouldn't expect you to take anyone's word, including mine, on your next step without getting satisfactory answers to your questions.
About rescuing, we all need it at times. Mental health issues are wrapped in stigma and judgment that make it difficult to admit that there may be a problem, even with great family support. I see your W as trying to find her way by going to MC with you and in asking for referrals to ICs. People don't choose to seek counseling if they think everything is OK.
I don't think you can fix her, that's not your job but you can support her even though right now that may be very difficult and it does require a certain amount of detachment.
None of this is easy and it is a tightrope walk at times. But as I said, I think you're up to the job. I wouldn't be revisiting this if not for the red flags I saw in your first posts along with the new one you threw up today.
Good luck.
Me 57/H 58 M36 S 2.5yrs R 12/13
Let me give up the need to know why things happen as they do. I will never know and constant wondering is constant suffering. Caroline Myss