The more I think about the way Barbara becomes Cheetah in the movie the more I dislike it. Max gives her someone's rage and prowess and that turned her into a cat creature? It makes no sense! Unless cats are also allowed to make wishes and he took the rage and prowess from an actual cheetah

There was a way to have her transformation make sense without changing the story too much. Barbara mentioned she's a cryptozoologist in her first scene with Diana. Why not just roll with it? She's obsessed with mythical creatures, particularly werecats, and when Max asks her what she wants she exchanges her original wish for becoming a werecat herself. Why would she want to stop being human? Let's say after spending some time as a pseudo demi-god she starts seeing all humans as weak and beneath her and wants to be nothing like them. It's a bit New 52-ish, but I think it's still better than turning into a cat for no reason.