Jen, just so you know, Remeron comes in an oral-disintegrating tablet that is easy to get into your daughter if she won't swallow a pill. I hope that's what the psychiatrist prescribed so you won't have to fight with her to get the medications into her.
I agree with Janet -- start the medications while the testing is going on. At least she'll start to sleep, her anxiety will lessen and she may even start to eat.
Hugs!