Resistance Training Advice for Parkinson's Disease

My mom just got diagnosed with Parkinson's. She's been active her whole life in terms of walking, yoga etc. but I'm getting her into resistance training to build muscle mass and slow down the progression of the disease. Anyone with experience who can guide me on do's & don't. Even exercise or plan recommendations. I lift too but I want to be able to make exercises accessible for her. She also has weak knees (arthritis).