Dark meat poultry, fatty hamburger, ground lamb, and canadian bacon are good choices. Of course, dogs in
renal failure are so nauseated, it's hard to get them to eat anything, so if she won't eat the low-phosphorus foods, just get something in her.
To counteract phosphorus, give her one or two Tums antacid tablets a day - or any indigestion tablet that is primarily calcium. The calcium binds with phosphorus and carries out of the body so it can't do further harm to the kidneys.