I figure that Wendy will regain use of her legs. In the 80's when Babs was paralyzed, paralysis was considered it. You were done. In a chair or bed for the rest of your life. Nowadays you hear about people recovering from potentially paralyzing injuries more often.
Wendy will end up the new Batgirl with Babs teaching her. The purpose of the paralysis is to make us wonder which one will be walking in the new series and which one will be in a wheelchair.