As a parent to two boys who 'look like girls' (both have long hair and one loves purple and pink), I notice a difference in the way that adults treat them when they think they are girls compared to when they realise they are boys. It's telling how often I hear other boys being told to be careful around them until they find out they are boys and then all bets are off!
What I am surprised by is the degree to which some PPs are able to categorise their children's interests so definitively (typicaly 'girly girl' or 'boisterous boy' type comments). Perhaps mine are more unpredictable than most, but I would hesitate to say that either particularly conformed to gender stereotypes or confounded them on any given day (apart from the hair and pink leggings that is!).
I would say my two both have about an even spread of traits that are considered masculine and feminine and I think that most of the kids I know do too. If you saw them at the park, you might think 'typical boys', but if you saw them at home, hosting an elaborate tea-party for a million soft toys, you would think the opposite.
I try to treat them as individuals and not pigeonhole them, but it's impossible not to let my unconscious bias play any role in my parenting. I don't feel as though their father or I conform particularly to gender stereotypes (dress pretty neutrally, relatively mainstream interests that are non gender-specific, work for ourselves, from home in mixed fields etc), so maybe this has had more of an impact on them than we realise.
Their best friends are a mix of girls and boys - my oldest tends to gravitate towards girls, but has one particular male friend that he plays VERY roughly with, but they are both into it and, as parents, we allow it because they are very evenly matched, don't hold a grudge and are careful not to go too far. My son has NEVER tried to play like this with anyone else, male or female, so I'm not sure if it's about 'boys being boys' or about the kind of friendship I have with the other boy's mum that we have allowed them to explore the urge to wrestle when otherwise I wouldn't have allowed it.
The thing I think has made the biggest difference has been that neither go to school. My oldest did for a while, and I was surprised to learn that at 4-5, they were already dividing themselves along gender lines with the boys not letting the girls play football and the girls not letting the boys be in their dance shows. I was really surprised at how many of those gendered tropes had already been picked up and were being regurgitated freely.
I don't think the school reinforced these ideas, but it was incredibly pervasive and it appeared to be ubiquitous and I suspect that it probably had more of an impact than most of the work that the school did on the same subject, which is a shame.