Oh God, the name of the guy got starred LOL...Well I don't think his name is relevant. I just gave it to you in case you wanted to do some research on who he is before getting your cat to eat his food. His name is D I C K Van Patten. I'm sorry MH, that is his name :)
Your cat should be given prescription food like C/D or Science Diet. BUT, if you do not want to use prescribed food, then think of what a cat with UTI needs the most: water to flush and get rid of bacteria. So, the more water the better. Canned food can be good for her. There is a commercial brand very good for cats called Natural Balance. It is expensive but it's got no by-products, fillers or preservatives, at least the label is free from those. The food is a bit more expensive than Iams, Science Diet or any other "premium" cat food but it really is better quality. The formula was created by **** Van Patten. I believe he was very dedicated in finding quality in foods for dogs and cats.
You can also cook for her. Some chicken broth with pieces of chicken, and heaven will make her happy. Just try and keep her motivated when switching her to better nutrition. I strongly believe in home-made recipes for our pets, or raw meat, chicken or fish. Don't forget liver and other organs which will give her the boost she needs.