Hello:
I'm glad they are feeding. That's half the battle right there. as far as them being a little thin, if they are feeding I wouldn't worry too much about them. They're not going to gain all their weight back in a day or even a week. The most important thing to remember is the deydration but it sounds like you have that well under control.
Keep us posted on how they progress. Good Luck!
Have a Great Day!!!