Gosh I'm sorry to hear that and am concerned. I've never been in this situation, so all I have is brainstorms, not advice from experience. So take it or leave it. This must be a bit scary for you too.

What is your relationship with her, do you or would you be able to ask her how she's feeling and / or mention your concern? Sometimes people can't "receive" care / love, but I think it's good to tell them how much you love and care anyway. Of course, it's possible she could get mad if she's feeling defensive. But that's a small price to pay for someone's life.

Would you be able to mention your concern by calling up the counsellor who facilitates the group therapy? Maybe she would have a good way to approach it.

Let us know how it goes

Take care, Grace