ok, there will be some young children who have some inckling about sexuality, but these are often vague & undefined ideas. on the whole, where young girls look v 'adult' e.g. make-up, heels, etc, they are either copying an image/person they've seen OR some-one has bought them those things.
now, if dd saw something like that, i would discuss it with her, but tbh, she would be more concerned about how comfortable the clothes are, and if they are pink enough (sigh). I think larger numbers of kids grow up in their own little world, unaware of more adult issues, or only through a vague hazey impression.
so, yes, i think young children should be able to dress in clothes suited to running & playing, rather than aware of how they look to others. BUT i am equally concerned about how boys clothing also trades on gender stereotypes, and whether we should in fact campaign for kids to be kids.