We have in the past used a kind of porage given orally by giant syringe. Made up by cooking coarse mix - or pencils would be smoother- in water with added glucose and a bit of salt or some digestive biscuits, into a thick but slightly runny mixture. The syringe is a catheter tipped 50ml one, the kind used with a tube for lambs, so it has a large outlet. I syringe this down a few mls at a time, a few times a day, as many syringes full as she will take. It gets the rumen going again - could add some yoghurt for that - but bypasses the need for her to have an appetite. Tempting greens are good too, especially willow tips if you have any. Digestives on their own can be tempting too, as they have crunch, plus sugar, salt and a bit of fibre - you might have to push small pieces into her mouth the first few times, but once they are getting better they love them.