Aimee, I'd call the pedi in the morning, just to check. Watch to make sure she's still wetting her diapers, and keep an eye on the condition of her lips and skin. Little ones dehydrate quickly (the quickest is when the stomach virus is manifesting both ways). After she's thrown, you should wait a few hours before attempting to give her anything. I've had doctors tell me anything from 6 hours to 12 to 24 (my doc was away and the doc who told me 24 hours was just a neighboring doctor who was covering, and he yelled at me and I ignored him). I don't think I've ever waited 24.
When trying to keep her hydrated, she doesn't have to drink a lot. The key is to not make her throw more, and get her tummy settled enough that she can start taking small amounts. It's a balancing trick with some kids, because dehydration increases nausea. At any rate, they lose more when they throw up, than they get from whatever you gave them that made them throw up. After she's thrown you should wait a coupleafew hours before trying to give her anything.
This morning, you can start her out with a tablespoon or two of of pedialyte. If she keeps that down, wait between a half hour and an hour, then give her another couple of tablespoons--up to an ounce. Go slowly. If she's kept down pedialyte over the course of a few hours (while you're doing the whole have-a-little/wait thing) you can start giving her more at a time.
An alternative, if you have a blender, is crushed ice. Crush two or three ice cubes in the blender. Feed it to her or let her eat it herself, by the spoonful. They take it in more slowly than they do liquids, and ime, it stays down better. This is what they gave me in the hospital, the two times I dehyrated, when I was little. If she keeps down the first helping, wait a half hour to an hour after she's finished, and make her some more. If you do that over the course of a few hours, and she keeps it down, then you can move on to giving her an ounce or two of pedialyte, and see how she does with that.
I'd still call the pedi to see what they specifically recommend once she's keeping down clear liquids like water and pedialyte. They'll probably tell you to keep her off dairy and fats for a day or two. I generally go with a combination of clear liquids, and then dry, blandish foods, and ginger ale, but my kids are much bigger.