I find Tom incredibly interesting for exactly that reason, though I think it's entirely accidental on EBD's part. I actually find it hard not to read her as basically trans, though I suppose that's me putting a v modern slant on it. The thing is, she's not like eg George from the Famous Five, or Jo in Little Women, who are tomboyish because they look at what their society offers them as girls/women-to-be and think 'sod that for a game of soldiers, I wish I was a boy'. That's a rational response.
But Tom goes to the Chalet School, learns that girls can do anything boys can do, that boys have all the same flaws as girls, and is largely cured of her internalised misogyny (and what a shit her father is! What contempt to hold his daughter, and presumably also his wife, in) - and yet retains this aspiration to 'be a gentleman', this semi-identification as a male. And we never get an authorial comment condemning the damage her father may have done in this regard (as we do for other parental failings - Eustacia, Emerence, Yseult) - so are we supposed to believe that the maleness is somehow inherent to Tom, almost as a coincidence to her father's vile indoctrination? Even as an adult, the impression is that she remains more male than female - and her mission work is exclusively with boys.
Cheddar I believe there is a long and glorious history of at least women managing to live as men at various points in time. I only know bits of it quite tangentially, as I'm more directly interested in lesbian issues/history than trans ones, so I've mostly come across it as being a way women have managed to build a home and a recognised relationship with their female partners, and naturally in most cases very, very little remains to indicate whether passing as a man was primarily about enabling them to conduct lesbian relationships, or achieve other goals in a hugely sexist society, or whether it was really more about feeling themselves to truly be male. I have to also say the examples which spring to mind all rather significantly predate the 1940s - but that's as likely to be because of a growing possibility for women to live together as female couples, rather than because early transfolk stopped existing, if that makes sense.
I am so excited by this conversation I almost wish I didn't have to go out now.
They would have been utilitarian navy blue bloomers, btw, I think. Didn't Guides (and Guiders) wear blue?