Where are you staying? Does it need to be walkable?
I'd make sure you trek out to Mills River and see Sierra Nevada. As far as the rest I have not seen many breweries will teenagers milling around. Certainly New Belgium wouldn't have an issue AFAIK with them being in the taproom or the deck. If you go over there, then cross the river and go to Wedge as they would fit your IPA and Stout bill.
If you like more traditional, then go to Dirty Jacks beside Green Man. It is still Green Man, but not all artsy fartsy Modern. Since you are there, go to Burial and also hit Catawba. All the breweries on the South Slope are mere minutes apart by foot. You could swing over to Ben's Tune Up and have some of their house made beer or Sake. Just beside it is Hi-Wire who is making some great stuff. As you were walking there you could also check out Twin Leaf. Bharami isn't far away either and if you walk up the hill you could always visit One World located underneath Farm Burger.
Since it is a single night, just go to the South Slope. The kids could hang out at French Broad Chocolate, see movie, or just people watch and smell.