How is she feeling now? Are there particular joints causing most of the problem?
Is there a plan in place for her to go on specialist meds for the RA? Does she have other conditions too, I wondered maybe fibromyalgia given the other meds she is on as a fibro flare can be horribly painful too.
I'm guessing she is under the care of a rheumatologist if she has been formally diagnosed. Worth checking if anyone from the rheumatology clinic can speak to her, there might be something like a specialist nurse helpline, although on mine it's a voicemail service and they can take a few working days to get back to you so best to get in early, especially with a weekend approaching.
Specialist nurses can often do things like give general steroid injections if deemed appropriate and speak to the rheumatology doctors around.
DIY therapy wise, if her joints are hot and swollen and painful then a bath might be uncomfortable, especially in this warm weather too. It's a personal thing though if she finds baths help.
Is she working with her GP and anyone else involved to help her with her mood, especially with the added pain and all that goes with RA on top?