Angels were always girls and boys when I was a kid in the nativity.
You just had to be blonde
See, I still remember the injustice of all the blond/e children being chosen as angels and Mary, while the dark haired ones were shepherds, inn keepers etc.
Even at a young age, I was aware that the part of the world where the nativity was set meant that Mary should have looked more like me! But the idea that blonde = virginal, angelic etc is pervasive. I wonder how many black girls are chosen as Mary for their school's production?
Obviously I don't feel like my life prospects have been harmed by it, but there is definitely a feeling that blonde is better and those many instances where it has been subtly pushed on me have all compounded that message, in the same way that gender segregation does.
It is the responsibility of nurseries and schools to work against the negative messages that we are all given by society and if that means encouraging the boys to don a pair or wings or a sheep costume instead of a beard and a tea towel on the head, that's great. If it means having a dark haired, dark skinned Mary that's as it should be.
Giving all children the message that they can be anything they choose can only be a positive thing. And no, I don't mean that a boy can actually have a baby, but tbh if one wants to play Mary in the nativity then its no more ludicrous than playing a sheep or indeed a pineapple (my DD was a bowl of fruit in her nativity!!)