DC restaurant - National Mall area, inexpensive, kid-friendly lunch?

We'll be visiting DC with our families and would like to find a kid-friendly, inexpensive restaurant in the area of the National Mall. It doesn't have to be on the Mall (i.e. one of the Museum restaurants - are they overpriced?), it can be nearby. Would prefer non-fast food (no McDonalds, Burger King, etc). Thanks for the help.