I would recommend distilled water. That's what several vets have told me regarding crystals/stones.
Sorry, I'm not familiar with the cranberry pills, so I can't really give advice on that.
As far as foods are concerned...Vets usually prescribe Hill's u/d, but I do not like the ingredients in it, and I won't feed it to my dog. He had seizures for the short time that he was on that food. I wish I could tell you which food to give your baby, but we homecook.
One thing you could do though...There's a nutritionist/dietician at the University of Tennessee who will formulate a homemade diet specific to your dog's health needs. I think she charges around $150??? I'm not sure, but that might be an option.
Otherwise, if you feed the dry Canidae, you should really serve it with equal parts water, meaning if you feed 1/4 cup of Canidae per feeding, add 1/4 cup of water to it. But don't let it sit out like that...Your baby would need to eat it right then, not to be left out all day. I understand that your husband does not want to feed canned food, but if it comes to your furbaby's overall health, I think it might be necessary. As long as you clean her teeth with a baby finger toothbrush or petzlife oral gel, your dog's teeth should be fine.
Those stones will not come out if her urine is not diluted enough...