I wouldn't worry too much about the role-playing or the clothes - they probably mean something quite different to a small girl (maybe a dream of being magically elevated above everything mundane and boring) - but I would put a little effort into exploring her values and ideas, listening to them, and challenging them if necessary at the right age. And making ones own values clear, of course.
We tried to delay our son's exposure to realistic war toys, but never forbade them. So he's run around and "killed" people like every small boy, but I also made it very clear that I did not want him pointing anything gunlike at me, because it made me uncomfortable. Because people really do die that way, and I did not want to play at that particular game.
To each their own sensibilities. There are things I wouldn't let my son (or daughter if I had one) wear, but that would be because they didn't understand the message it gave to the rest of society.
Winter riding is much less about badassery and much more about bundle-uppery. - malkin
1995 Kona Cinder Cone commuterFrankenbike/Selle Italia SLR Lady Gel Flow
2008 white Nakamura Summit Custom mtb/Terry Falcon X
2000 Schwinn Fastback Comp road bike/Specialized Jett