Just take them to "the brasserie around the corner". They'll love it just like my family does.
No, I'm NOT joking this time. Good food, fair prices, relaxed atmosphere, good selection of kid-friendly food, and good wine or beer for the parents, too.
We go early enough (~17:30) and still get the cheap lunch menu prices, too.
Enjoy!
BTW, OP, do you speak a little French yet?