Hello.
A few questions before replying properly ...
Was the Benazapril prescribed for high blood pressure and, if so, is the BP now controlled? Or was it prescribed to improve blood flow and volume to help the kidney disease?
Plavix is an unusual medication in dogs. Are you aware of why your vet prescribed this? If not, please ask. If it is for glomerular disease, then it is not the best medication. Studies suggest plain aspirin is actually slightly safer.
Amlodipine is a calcium channel blocker and typically given for blood pressure or another circulatory condition. It is also used to assist kidney failure, by improving blood flow. However, it isn't the first choice or recommeded first choice in kidney failure for an otherwise healthy dog.
The diet sounds fine, but feeding the daily volume of food portioned into 6 or 8 smaller meals given every 2-3 hours would certainly help the kidneys deal with it. It may also reduce nausea and bile production. These smaller portions remove much f the stress placed on kidneys by food intake - although I realise it isn't always practical to feed in this way. And if your dog is small for the breed, then tiny portions could mean one or two desertspoons at most.
Creatinine at 2.5 puts her into stage 3 (just) of kidney failure, assuming other levels confirm this. Lower protein is certainly therefore appropriate, but importantly, high-quality rather than low-quality protein is just as important. That means either a good quality kd dog food (canned) or human grade meats and poultry.
Even more important is the phosphorus content of food. Phosphorus must be severely restricted, so make yourself aware of what is in the foods you are feeding. You didn't mention phosphorus in the bloodwork - has this test been done? If so, what is the reading?
Tony