Is there any way to get Maelys out of her catatonic state?
There are actually two ways
1. Ask the infernals for "help" Result She's now a redskined futa rage demon.
2. Ask Malice for help in the castle dungeon, Result complete personality change, it might b her body but it's not her.
I would recommend for now to keep it in your pants progress through the dialogue as you did before but DO NOT FUCK HER!