What does that actually mean though? There’s no difference between their brains at all at birth (any “gendered learning” is merely conditioning). Hearts are the same. Internal organs the same. Their genitals are different
Actually, that's not entirely true. Numerous studies have shown differences between girls and boys brain function and development from a very early stage before any 'gendered learning'. Boys and girls are not the same. They think differently, they process information and emotions differently, they learn differently and at different rates.
Physically, there are obvious differences not just limited to genitals and reproductive organs. There are differences with body composition, bone density, muscle composition, physical strength....it's why males and females don't compete against each other in competitive sports for a start. If you go for any blood test, you'll find most markers have different 'normal levels' for males and females and don't even get me started on hormones! Boys and girls are not the same and trying to treat them so can be extremely damaging.
(I have other theories about the rise in mental health which are far more compelling than children having certain colour restrictions! Will post those later if I find time.)
I tend to speak as I find. I encounter a lot of young people in the course of my work and have met many gender neutral and non-binary teenagers and young adults. One thing I've observed about them all is that they all have some sort of mental health issue and, on talking to them, they seem lost and without any real sense of identity. I don't believe it's a coincidence.
And I'm not talking about kids just having 'certain colour restrictions' (I couldn't care less what colour a parent wants to dress their baby in) I'm talking about the whole concept of not being attached to any gender and being a 'human child' instead of a girl or a boy.
Of course I also have lots of other theories about what else has led to this increase in mental health issues too....this is just one factor....but I don't want to veer too far off topic.
I genuinely don’t understand why dressing her in pink as a baby, rather than all the colours of the rainbow (including pink) or buying her a pink bouncing zebra rather than a black and white one would have benefitted her?
It wouldn't have benefitted her. Nor would it have hindered her. That's the point, it doesn't matter either way....if people want to dress their kids in pink or blue they should be free to do so without criticism. They're still a boy or a girl, with or without the stereotypical colours. In my experience, kids don't have lifelong issues associated with being dressed in certain colours as a baby. The problems seem to arise when kids are told they are 'neither' or encouraged to choose whichever they want to be at a very young age. God knows what I would have said if you'd asked me who i wanted to be as a pink hating, boisterous, boyish youngster!
It's our responsibility as parents to help our kids learn who they are, to steer them and embrace their differences....whether gender related or just in their own individual strengths/weaknesses/interests.
So, linking back to the OP, I get it. She thought she was having a girl but now she's found out it's a boy and she's in shock. Boys and girls are not the same so it's taking her some getting used to. Understandable......whether or not she went a bit far with the pink thing is irrelevant really and besides the point.
Anyway, It sounds like your DD has a great balance and is finding her own way in the world and learning what she does and doesn't like....just like I did as a little girl. Gender should never hold anyone back. Good luck to her....it's a crazy world out there now lol.