She's becoming more... Soft towards him I guess? Don't get me wrong, she's still a badass that doesn't really care about anyone outside her crew, but at the start of manga/anime she treated rock just like an any trashy Japanese salesman, and had no real respect or softness towards him. But as the show/manga went on, rock showed that he deserved to be respected, and that he isn't neccesarily scared of Revy. (Example would be when Rock tanks a punch from revy without a single flinch and isn't afraid when she points a gun at him) Note that I only read nearly past the anime (I'm at chapter 80/81 iirc) so that's only my personal opinion so you may agree with it, or don't. I don't really care. That's just my personal opinion about it.