Hi,
Are you watching her while she tries to eat?
It might be worth closing the tub and leaving the room once she has struck and coiled to see if it is simply her getting stressed at being vulnerable while eating ( doesn't happen often with established snakes but I've seen it with hatchlings ).
Or it may be worth having the vet look at her throat again in case there are any problems that would cause her pain when food reaches it. Try something a lot smaller like a hopper mouse?
Ask the vet about carnivore diet if nothing else helps.
dr del