I can empathise with that Snow - it's an idealised fantasy but a very human one and part of human existence, we all have those losses of the ideal that might have been. Whether it's the happy childhood and competent or non abusive parents (trying to imagine my DF having a tea party with me.... imagination shattering in the process), the children that you might have birthed, the body that might have worked properly, the marriage that might have been. Growing up gay I'm sad that I grew up surrounded by images of heterosexuality and a total lack of any role models of what a gay woman was or even that one existed. It's not a big issue, but that sense of sadness is there.
More sadly, yes, the average girlhood contains some nastier things like the very probable sexual harassment or assault that most women have somewhere in their childhoods, the body shaming and all the rest of it. But I can well comprehend that idealised sense of what might have been possible for the writer in a less gender strict and gender scary world, if they had been able to express themselves as they wanted and not been afraid to do so. That quote is so poignant to me because it's filled with realism and good sense: "I often tell friends that I'll always be transgender; that there is no surgery that can make me have been born a girl".
I'll gladly support that to the hilt.