I think it will be hard for them to work Leah into the show, if she isn't living with/near Shaun. The show hasn't really been using her very much as it is.
It kind of sucks because Shaun deserves to have friends, and Leah seemed good for him. I wonder if they will have Shaun reach out to her to move back in if he and Carly break up? I would assume she would reject that.
It also sucks for Leah to have to move out, it looks like she did it pretty quickly. I wasn't some huge fan of hers, but it just seems crappy to be in her shoes.