Keeping turtles for kids...?

I've got a 35 litre Betta aquarium, currently unused and gathering dust. I was going to put a Betta in there, but never "got around to it"! However, my daughter has taken an interest in these little turtles at the lfs when i've been buying stuff. Now, is this tank big enough for one of these, do i need heater, filtration, and what do the feed on? I know i could go researching, but i haven't the time, so basically know nothing about them! She's only 3 but can name every single coral and critter in my reef setup, so she'll end up teaching me! lol :)