Here is GirlGuiding featuring a 'transgirl' in Rainbows, which is for ages 4-7.
The whole thing is based on stereotypes and 'what will people think'.
"Jane and her husband Mike started noticing that Rainbow identified more with female characters, toys and books when she was 18 months old. ‘Some people suggested we just say no, encourage her to identify with the male characters, but how can you explain that to a young child? To what end? No to playing with toys she loved or characters she loved to pretend to be? It felt cruel to say no, to the say the least.’"
There is a lot more in that vein.
Then :
"‘One day she said to us in a quiet voice, “My real name is Rainbow”.
'Until you’re in that position as a parent you cannot know how you will react. I could have laughed and said, “No it’s not.” I could have compartmentalised her life: “OK you can be Rainbow at home, but not at school." We didn’t take this route. Instead we asked, “Can you tell us a bit more about how you feel? There are some boys who like all the things that society thinks are for girls but know themselves to be boys, and there are some who feel like they are girls inside."
‘My child explained, “It’s the second one.”"
That sounds like proof positive, right?
To me it sounds like the boy child has taken on board that, in his family, it is essential to actually 'be a girl' in order to live as he wants.
girlguiding.foleon.com/guiding-magazine/guiding-summer-2022/rainbow-girl