Hi. There are very many causes for high protein levels in a dog's urine, the most common being diet - though other causes can be more serious. I would start writing down everything you are feeding her, including all treats, and then pass this information on to your vet when you next see them. It is extremely unusual to find a dog this young suffering from kidney failure, so I would doubt that is the case here - however, the blood test conducted by your vet has determined there is no renal failure - so don't worry about that. I'm no expert, but it's interesting to note that the cyst walls of the giardia parasite are protein-based. As it is so recent that your dog has been treated for giardia, it could possibly be that some of the breakdown of the cysts are being released through the kidneys. It would certainly be worth raising this with your vet, who will know far more about it than I do.
It strikes me it could be too early to conduct the spaying of your dog, particularly after being treated for giardia and while she has this high protein count in her urine. Spaying can be conducted any time after about 6 months, and although your puppy is within the right time frame, the surgery does present some risk. Like all surgery, it is far better for the dog to have a well-charged auto-immune system and to be as healthy as possible. Hope this helps. Tony
An infection can cause the lab irregularities you described. I suspect you will find a bladder/urinary infection.
Diana