Thanks everyone! I will definitely give her some extra Canyx snuggles today
They did a urinalysis, not sure if that's the same as a culture or not? They said if it comes back again, they'll have to send the sample out to a lab while she's on the antibiotics to see how the bacteria is responding - or not responding.
I've been giving her a cranberry supplement for the past week or so (Solid Gold something-or-another). Haven't tried the ACV - she has a touchy tummy, so not sure if I wanna go there just yet. It is good stuff, though! I tried it myself last year, but it apparently doesn't mix well with acid reflux...lol.
She does really well on TOTW food - I'd hate to change it (especially since I just bought two new bags) and there's the switching-food-tummy-issue again. And I'm not a fan of Science Diet, but if they think it will help, I'll try it.
I also give her Nupro Joint & Immunity supplement and probiotics. I was mixing plain yogurt with her dinner to keep her "regular" while on the medication. The vet didn't think these would interfere with the antibiotics at all...?
Although it's not exactly a good thing, I'm hoping that it's just a resistant bacteria that a different medication - like the cephalaxin will take care of.

I wish I didn't worry so much.
ETA:
Just got back from the vets. The UTI came back - obviously resistant to Clavamox. They took a sterile sample and are sending to the lab for "culture and sensitivity" and put her on 68mg of Baytril. We'll see I guess. I hope this antibiotic takes care of it.

I didn't get a chance to speak to the vet - they squeezed me in. Will have to wait to see what the lab comes back with then deal with food changes and all that jazz after.
<<<sigh>>> I feel so bad for my girl.