I cannot add a whole lot to what the others have already told you. Please try and get your mother off the Prednisone as soon as possible, although she will need to be weaned off of it by slowly reducing the dose. Generally, steroids are started out at a very small dosage, then gradually increased until the recommended amount is reached. When (or if) a person can go off the steroid, the procedure must be reversed. There are a lot of natural anti-inflammatory herbs and supplements that will be much safer. One that is necessary is Omega 3 essential fatty acids, fish oil is often said to be the best, but a lot of people don't tolerate it well. Fresh ground flax seed is excellent. I like to mix a couple of tablespoons with some unsweetened applesauce and a dash of cinnamon for a tasty breakfast. You can also add a little sorghum or Maple syrup to satisfy a sweet tooth. English Walnuts, avocados, and raw pumpkin seeds are also good sources of Omega 3 EFAs. Herbs like turmeric, ginger and Cinnamon also have anti-inflammatory properties. Brightly colored fruits and veggies have lots of anti-oxidants that can control inflammation in the joints. A good green food powder will also provide anti-oxidants and help her with alkalizing. You might also want to try anti-inflammatory enzymes such as Bromelain, Nattokinase or Serrapeptase that reduce inflammation and improve circulation.
My Naturopath suggests a diet of 80% fruits and veggies, with a lot of them raw, 10% animal products, this includes both meat and dairy, and 10% grains and starches. A diet like this is anti-inflammatory, alkalizing, and is good for those of us who are insulin resistant. One can occasionally enjoy a treat of meat, dairy and grains and that makes it easy to stick to the healthy fruits and veggies most of the time.