She should be fine. Firstly, she reads the person, and then she reads Carla. It's more so if Carla is upset she gets WAY over protective. So if the two were to break out into an agreement Jem would growl in warning for sure. She wont like Ethan until Carla does, but she'll only growl because Carla will warn her not to attack him xD. Jem may come around a little bit if Ethan walks her too. Jem LOVES walks OMG. She'll love Kimberly's place because she can stay outside all day in the backyard XD