I'm a cranberry pill believer, too. I've used them for myself but also for the pups. If I suspect a UTI, I give them cranberry pills just until I can get them to the vet as soon as they open. The dr told me that something in the cranberries helps to keep bacteria from sticking to the interior lining of the bladder, so it can help to prevent UTI's, and can be a temporary comfort during a UTI until you can get antibiotics. Cassie had a UTI a few months ago, so I added Wellness food to her diet b/c it has blueberries in it (similar to cranberries for prevention). So far, she hasn't had another UTI yet (knock wood!).
Also, when I've had UTI's & kidney infections, the odd thing is that I just don't feel like drinking anything for some reason. Of course, that's the worst thing because the fluids are vital.
Maybe that's just me though. If Grace likes canned food for a treat, you might have luck making a soup out of it by adding more water or low sodium broth. That usually works for my pups anyway. I hope that Grace kicks this quickly, poor girl.