I was going to mention maybe some kind of pellets, or maybe some full feed type feed; something that will give her a bit of energy, and sustanance, without making her hot. Basically, though, at this point, I'd be giving her pretty much anything (safe) that she will eat. Cubes, treats, apples, carrots, etc...anything to keep her stomach digesting, and giving the baby some nutrition. Obviously keep the 'treat type' things to a safe dosage, but if she'll eat them, let her have some. To help her drink more water, you could put some Honey, Molasses, or unsweetened coolaid in some of the buckets...that will give her water a pleasant smell, and she may be more inclined to keep drinking. Perhaps you could get some probiotics for her, as well... but make sure you ask the vet if they will interfere with the meds she's on currently...usually they don't, but you want to make sure.
"The ideal horseman has the courage of a lion, the patience of a saint, and the hands of a woman..."