Other than swimming, what is the best type of daily excercise for a person with rheumatoid arthritis?

I have a loved one with RA. She is young, 29 years old and has been suffering from RA since she was 17. The pain consumes almost every joint in her body. She has flexibility during her workday (it is at home) for her to exercise throughout. What type of exercises and stretches can she do at home to alleviate both pain and stiffness?