Rheumatoid Disease, perhaps more accurate than RA as it is truly an auto immune connective tissue disorder. In English that means it impacts skin, tendons, joints, anything with connective tissue in it. Your body attacks its own connective tissue, essentially. The strategy is typically to prevent damage and maintain joint range of motion. You want her seeing a smart rheumatologist, who she will get to know very well until they retire or she dies of old age.
All, and I do mean ALL the drugs for rheumatoid are nasty, a lot of them are old chemotherapy drugs. Trick is to get the right meds, in the right combination, where it mediates the immune response adequately for you to have a life, and does not make your liver turn into cottage cheese or something else untoward. This is different for every single person, and changes over the course of the disease. Some people are just on methotrexate or some other old school drug, and it works for a long time, others require more aggressive treatment. The immune system is out of whack, and the meds keep it tamped down. The meds are going to suppress the entire immune system, so people under treatment are more likely to get infections. When they do get infections, they may not get the redness and other signs of infection, so the infection can sort of take off before you are wise to it.
To put it in GRM terms
Imagine you have a car with no rustproofing and you are going to move to Michigan with salty roads. You would want to stay on top of washing the undercarriage, or your car rots out from under you, because rust never sleeps. Same deal with rheumatoid. It is always working on you, it is just a matter of mitigating the damage. You have to keep moving, or your joints freeze up on you. The old adage, if you don't use it you lose it, counts double for rheumatoid patients. You don't want to wear the joints out any faster than the disease is doing, so you stay away from running or other impact type of exercises. Better off with yoga, pilates, stationary bike, swimming, that sort of stuff.
Read up on it, find an RA support group, do all you can to educate yourself and act as her advocate in her treatment.
If you are on prednisone, be advised that you DO NOT want to just stop taking it. You have to taper off that scheisse or it is liable to kill your ass.