I hope he's gets some strength and starts wanting to eat on his own. The red eyes I took in took a bit to come around too.
That's awesome that your sisters doing a frog saving project. My daughter did one too. I took some frogs to school for her. We made lots of educational posters and played frog games. We even made dirt pudding with gummy worms to celebrate.
I'll link some sites for you/her to make the project easier.