I'd say trust your instincts, if they are saying this isn't the right fit, I think 5 months is adequate time to have determined that. And it can't be comfortable having the feeling that you need to look out for her feelings.....though that is something I think perhaps you could discuss with her and it could lead to a greater understanding of why you do that sort of thing, if that is part of your pattern. Maybe you don't need to stay much longer with her, but could have a discussion of that as part of closure sessions, so to speak.
You have my support whatever you do......