Hi daverisk,
I know I need to keep things calm when she's here, be supportive, not ask a lot of questions about what's going on... .any other suggestions?
This sounds like a good plan to me.
You might wait for her to initiate the conversations about her treatment, and then really listen with empathy. Letting her know that you are here for her, without trying to solve her problems (she is responsible for engaging in her treatment).
I know it's easier said than done! Let us know how things are going.
heartandwhole