Wow, I don't know. Did the vet say how long it should take for her to adapt? Maybe there is still some numbness in her tongue from the surgery. Sounds like what you are doing with the baby bottle is good. Maybe make her soft food real soupy and she will get more water like that. My guess is that she needs time to get used to it. She probably feels like what we feel like getting home from the dentist and our tongue is still numb.
If she isn't doing better after several days, do you think she could learn to drink from a water bottle (like the kind for rabbits)? I don't know - that might be a wild idea, but it's an idea. I think she could just hold her tongue on the ball part and the water will come out on it's own. She wouldn't have to do so much lapping, just swallowing. I've never seen a dog drink out of those, so maybe that's a stupid idea. LOL (Forgive me if it's idiotic)
Best wishes for her speedy recovery.
Cody's FOREVER proud Mom