You will know if she is dehydrated by the number of wet diapers she has. At her age she should have 5-8 wet diapers.
Have you tried teething pellets, or they now have teething strips. Walgreen's sells both forms, by the other baby products.
Have you talked to your Pediatrition? I would go and get the teething relief products first, and then call you daughters do c in the morning...
Have you tried any tylenol? Or frozen fruits? My youngest daughter is 15 months old. And when I KNOW that she is tething, I will give her yogurt and frozen blueberries. Make sure to cut up the blueberries so that no choking can occur. But my baby LOVES them. You could also try:
Annabel Karmel BPA Free Fill and Freeze Puree Pop..basically you make REAL fruit popsicles, and trust me when I say they are a life saver for both Mom and Baby!..
Also there are some mesh like bags that you put the frozen frozen fruit in and let them suck on that..which due to your babies age, that may be the best way to do it. This way baby only gets juice, and there is no risk of choking. I cannot think of the brand name of it, but you can find them at a babies r us. My daughter was totally addicted to it, especially through her early teething. Good luck!
Good Luck