Have you given her vitamin C supplements? C will help raise the acid in the bladder and help keep the UTI's at bay. I would start with 500mg(human grade) of EsterC and over a week double the dosage, then you could go up to 2000mg(1000am and 1000pm) to keep that acidity level high. C isn't stored but flushed out of the system so you can't overdose it. Though it can be hard on the gut when first introducing it.
Thank you so much! I haven't tried vitamin C yet, but I will definitely give it a shot!