Aloha Blast,
Have you tried something flavored? Pedialyte is good stuff. They even have a frozen flavored version. Most of the times, kids don't pass up frozen sweet stuff. If you don't want Pedialyte, juice cut with water works too. I had to do that for my kids before. Then they will drink water after to clear their palate.
Sometimes, plain ice chips work too as does ice water. I don't know what it is with kids and cold stuff. But then again, I like it too.
When I was little and had stomach problems and didn't want to eat, my mom would give my hot ovaltine (made with water, not milk) and soda crackers. That seemed to help. I tried it with my kids too and it worked. They get fluid from the ovaltine mix. Coupled with the soda crackers, it seemd to settle their tummies. If the soda cracker is too hard for a 1 year old, you can break it up and toss it in the liquid to soften it. And since it is sweet, they drink water after.
I am glad DD2 is better. Good luch on hydrating.