What would happen if your dog ate 15 naproxen pills?

Our dog recently ate 6 Naproxen @ 500mg dosage on accident. She started throwing up shortly after eating them and had to be rushed to the vet ER. The vet there told us that 1500-1600 mg is fatal in a dog. Our dog ate between 2500 to 3000 mg. She has been on an IV catheter for 3 days and has had to have a charcoal induced vomiting round and many meds for her stomach not to form ulcers. Most common results of this are gastric ulcers and kidney failure. It is extremely expensive treatment and a very serious illness.