Take them downtown to Market Square to La Margarita or Mi Tierra.
Mi Tierra is open 24 hrs a day. Both are excellent. You can park in one of the lots there or at River Center Mall parking garage and ride the trolley there for 75 cents. Now, knowing that., down on the River Walk is "The Original Mexican Restaurant.".,., the food is inexpensive but is it good.., not a lot of flash or cash but just right. It is the oldest restaurant on the River Walk. Any of thos I mentioned are good. Thats where we have been eating for years. They do get busy at times, so be patient. Its worth it.