I think you are greatly over-estimating Rose's fragility with respect to getting hit.
For one thing, Rose is known to hard-spar with male fighters. There's a story that Pat Barry tells about some dude that was sparring hard enough with Rose that it pissed Pat off and so he told that dude he'd have to spar with him (Pat) next. Notable about that story is that Rose wasn't the one who had a problem with how hard the sparring partner was going, it was Pat who got upset. Nor did either Rose or Pat stop the hard-sparring session with that dude.
Rose also helped Valentina by hard sparring with her for two fight camps, and Rose mentioned that Valentina has a reputation for hurting sparring partners because of how hard she hits when hard sparring. That didn't scare Rose away from being Valentina's sparring partner though. And, while she was talking about it, I think Rose was sporting a black eye that she had gotten from a session with Valentina, if I recall correctly. And even having tasted that power, Rose has said that she'd like to fight Valentina for real one day.