I have the same problem and it was diagnosed as Trigger Finger by an orthopedist. I was told that I needed an operation on my hand to sever the tendon causeing the problem.
You also might try the non-prescription corticosteroidal cream. This is a so-called "transdermal" medication. It is absorbed through the skin. Use it 12 hours after the injections. The trick to obtain optimal performance is to thoroughly wasg the hands in room temperature water, removing all oils. Rub this in tenderaly, but throughly. You might also try a small dose of vitamin E. Certainly no more than 200 IU (but check with your doctor, ESPECIALLY if you are on anti-clotting meds). Vitamin E can be dangerous. But it does improve micro-circulation. Every teensey bit of blood is precious, however you might want to ask for a hematologist to take a peek at the blood cells. Good hydration is a factor.The ratio of fluids to solids can change dramatically causing blockage in the tiny blood vessels.
Try some glucosomine and condroiten. She needs a medical specialist, M.D. type. Ocasionally these problems are caused by blood cells sticking in the tiny vessels. Aspirin is commonly prescribed for this condition. And omega-3 fish oils and cod liver oil which increase the lubricosity of the blood. But check with your M.D. before administering baby aspirin.