Sorry to that your Mom is suffering so. But I believe I would find another NH for her.
I have suffered all my life w/UTI's,and I have had every test known to man and there is only one answer I get and that is some women just have alot of them and for no reason. But I have reduced them alot by taking Macrobid 100mg, each day. So you can do something about it. If your Dr. won't agree with you find one that will.
Good Luck