"If you're going to keep insisting that I have a thing for Charlie I am going to shove my broom up your arse." She might not have Auror training, but Hestia was not exactly one to shy away from fights. And despite what some people may have thought, she wasn't a bully in school. She was just prone to getting to little skirmishes with various people. That was all.
Hestia, for the record, was not interested in Charlie. It would be like wanting a brother or something. Hestia didn't think of him like that.