Sorry for your troubles.
A cheap solution for UTI's is vitamin C, Cranberry extract, Golden seal tea.
Add meat stock to her water to encourage her to drink more.
Also Apple cider vinegar is very good for this and general well (being mixed with water).
You can also improve diet by adding some raw and find better water supply for her. You want soft water free from calcium and lime. I also think Kelp is a good nutrient for dogs in general.
More on UTI's
Canine Kidney Stone and Bladder Stone Prevention - Whole Dog Journal Article
UTI and bladder stones