For a little while yet, it's about strategy and not about who is more likeable. Nancy was not dropping much weight and was not helpful in the challenges, so it made sense to send her home. Conda still has a lot of weight to lose and she's young, so should be able to drop weight and see a good gain in strength, too.
She is a typical Mean Girl, though. Has a couple devoted "followers" and the rest are just politely putting up with her. If she does not in fact contribute much to the team, she will be gone pretty soon.