In Chinatown, further down on Cermak, our Chinese friend alwys takes us to restaurant 65, where we have always had incredible food-
if your child likes shrimp the shrimp and walnuts are wonderful and not too exotic- (which the crab in black bean and ginger can be over the top since it comes in the shell- but it's wonderful also)
Greektown is also a great suggestion, since something like lamb chops are relatively familiar for those who don't want to try different entrees-
often they will do 2 chops instead of 3 at a lower price if you ask.
My kids also love Italian- and if you can reserve one of the semi-private rooms in the the Village level of the Italian Village
http://www.italianvillage-chicago.com/ these are very fun to eat in and quite cozy-the decor is really delightful and the food is old school Italian and will be more familiar to 13 year olds.
If you can't get a reservation here- going early and tipping may also be a strategy that works....