My 3 y/o likes pink and dresses and things like that. It started when his little sister was born and people sent us a ton of pink stuff.
My husband and I don't love pink or super "girly" style stuff, for either of our kids, but when our son wants to wear a dress to to the playground, we do not make a fuss.
I don't wear nailpolish, so that hasn't come up as an interest for the kids, but if it does, I will limit their access to polish as its pretty toxic.
http://www.slate.com/blogs/xx_factor/2012/04/13/toxic_nail_polish_lies_found_on_beauty_industry_labels.html