If you pinch your daughters skin carefully does it spring back right away or does it take time. If it takes time she is dehydrated, you can also tell this by looking inside her mouth near her lips, if they are very dry or not.

If you have a syringe can you squirt bits of water far back into her mouth, even while she is sleeping. This way it goes in to her. The hydrolyte iceblocks are a great idea but they are very sickly sweet. Even if you can get her to have a water ice block like a Zooper Dooper or something that will help.

Goodluck and I really hope that she get's better soon.