Wheelchairs have their own seating. On the left side of the Mark Twain dock.
The seats are pretty good. YOU do have to sit on the ground. I took my dad one night and we got there at 7 for the 9 show as it was crowded. Also there were people renting wheelchairs just to sit in that area. They let our entire group sit together. Me, Mom, Dad, DS4 DD 18 mos. At the time.