Yes I would also think milk fever, possibly combined with ketosis, so a shot of Calciject (if the vet can do this straight into a vein it will wirk so much quicker) and also some energy drench, like propylene glycol unti, she is eating again.
One of my nannies was off food for a few days after a difficult and vet assisted kiding, but would always eat fruit and veg, some oats and some goat mix (but even now 2 weeks on she is not touching her dairy nuts!)
A long acting antibiotic would also just mean if there is any infection it would clear it up.
Stuff to try from outside: ivy leaves, dock leaves, dandelion leaves (and flowers), comfrey, some willow branches.
Hope she is on the mend soon, Anke.