I do not recall if it is ever stated how Cutter John ended up in the wheel chair, but Bobbi most definitely has legs. She is sitting on his lap.

Edit to add:

Cutter, a Vietnam War veteran using a wheelchair due to paraplegia from a war injury, was one of the county’s most well-liked citizens.

Cutter claims he was injured outside Quảng Trị in 1969, in a booby-trapped tunnel. He says that three of his buddies risked their lives to save him. Because he was inside a tunnel, he probably was a tunnel rat during the war.

Edit: Oh… I looked back at the previous posts… this is part of a series.

Yes, at this point in the strip it had been ongoing for 17 months, and ran for another 7 years.