Hey...
I can relate. I went through some pretty intense depression last year.
At that point, I had lovely supportive parents, was studying engineering at a top world ranked university, had friends I could talk to and yet, I felt worthless and wished I was dead. I felt even more worthless because I had all these things going so well for me, and yet I didn't appreciate them and so wished I was dead so someone else could get the benefits.
For me, the medication helped. The counselling didn't help that much - mostly because I felt that the counsellor didn't care. (In reality, and in hindsight, I think she did care, but was clinically detached - just like they teach you in med school)
I can't help with the WT side of things - maybe getting a counsellor who has some experience with cult mentality can help there...
But from your side, let her talk every day. You don't have to say anything to her, or even remind her of all the things she has going good... for that may just make her feel more guilty about feeling the way she does. Just let her talk to you, tell you about what is making her sad... or if she can't pinpoint what it is, then just tell you what she did in the day.
Important - encourage her to get some exercise! Go out for a walk together every day if you live in the same place. Walk kids to school. Go for a swing in the nearby playground when all the kids are at school. Do some yoga. ANY exericse, even if it just gets her out of the house for only 15 minutes, will help.
Lastly, ask her to talk to the doctor about increasing her dosage. I've been on 30mg of Citalopram for the last year. I call them my happy pills :) While the medication controls my sadness, suicidal impulses & crying bouts.... I'm working on building up a positive mindset, getting qualified in a field I love and enjoying life.
I sincerely hope she gets through this.
*hugs*
Dee