What is her activity level like? I have the same problems with eating; i pretty much have to force myself every time, but when I am active all day it is easier to eat. Sometomes, I even find myself wanting to eat.
Another option is try preapring lighter meals. Sounds crazy, i guess, but when I try to eat, say lasagna, I find I can't even eat a bite; all that cheese and meat sauce is way too heavy (I love lasagna, by the way, but I still can't get it in sometimes) If I have some fish, or a salad, or something like that, it's way easier for me to eat, and some calories is better than none.
Is your daughter on Miralax or go-lightly or anything like that? Part of my appetite problems used to be constipation, and I think it was quite a while before my doctor at the time realized it. Anyway, that stuff helps, especially in the mornings.
Also, instead of having an entire meal in one sitting, perhaps try to encourage her to snack throughout the day. It's way easier to eat just a little bit every hour or so rather than eating a whole bunch in one sitting. Triscuits are great; despite the advertising, they don't really fill you up and they have decent calories. I like the roasted garlic flavored the best, but your daughter may be different. =-)
If nothing else works, try getting her to drink something. Not scandishake (it goes back to foods being too heavy); maybe just fruit juice, or something. Drinking is always easier than eating, and fruit juice is alays yum. =-)
