It turns out she is one of the fairly small percentage of people who develop serious
kidney problems from
metformin. She had to stop it completely. Over the time she used it however she was also being extremely careful with her diet and lost a LOT of weight, so her diabetes is not so out of control anymore. Now she uses a once-per-week injection of Bydureon, and her diabetes is very well-controlled. Initially she used a helper drug with it, Glipizide ER, but she no longer needs that.