Does my mother need a Medicare Supplement?

My mother has been in a nursing home for a couple of years. Here Medicaid had been covering her medicine, but I guess not any more. My question is what kind of Medicare supplement do we need now? I have no clue which is the best one. I mean I really don't know which supplement is the best. I need one that will pay for her medicine so that I won't have to. If anyone has any suggestions let me know.