Thanks so much everyone. I am just letting her sleep it off at the moment, and dribbling water into her mouth every hour or so. She looks really black and blue on her face, bless her. I think she was very lucky that the geese did not break her neck.
Going to try a selection of things to tempt her to eat a little later on, and am looking for some of the things you all mentioned also. Someone also told me electrolytes

?? Anyone tried that? Have given up on the apple cider vinegar, as I can't find the cloudy one anywhere, only clear!
Sending my husband out for mealworms later, and will make him hand feed them to her as punishment (he is a vegetarian you see, so will find that task very stressful! lol)
The vet has told me to keep her back moist, so we have damp cotton wool to help with the inflammation at the moment. In 48 hours we need to replace that with some kind of antiseptic cream - I was thinking of trying Sudocream - works for my kids?? Anyone ever tried that on chickens, failing that savlon, E45 or the other alternative suggested was honey?