es have you tried warmed Liquivite or failing that cat milk - both are helping Gracie with the fluids and neither can really do much harm
Also another staple for us is liquidised kitten food with added Evapourated milk - Gracie loves this
Just a thought and at this stage anything that gets them to eat or drink is a bonus - Gracie is currently having her secret bowl of cat milk with me in the study she is on a bottle a day for herself!