I've never had brunch in Mt. Airy, but I know there are a few places that offer it.
Cresheim Cottage
NXNW
Geechee Girl Rice Cafe
You can also get breakfast at the:
Trolley Diner
The Point of Destination Cafe
Mt. Airy Breakfast and Lunch
There's also High Point Cafe and Coffee Junction.
We usually go to High Point since it's just blocks away. The food, coffee and service are great!