She once saw an article, on the library's microfiche reader that it is likely she knows how to operate better than the librarian, that made it clear that even before the Second World War, it was possible to turn a boy into a girl.
She immediately decided that she wanted to do that, that it would resolve a fundamental bitter ache in her heart. No matter how much it would cost her. And she knew that it would cost; was intimately familiar with price and privation in ways she shouldn't have had to be, at her age.
The existence of magic, however, found in the books at the furthest back of the attic, in a locked trunk that had more room on the inside than the outside, came as something that was - mostly - surprising, and showed her possibilities untold.
Unfortunately, she doesn't know how to make them real - yet.
That is what Hogwarts Academy of Witchcraft and Wizardry is for. And, for that matter, this shopping trip into..."Diagon Alley", via the "Leaky Cauldron" pub.
...Wizard naming sense is about as good as their discretion. Which is to say, 'not', or alternatively, "blatant as a jackhammer at midnight on Sunday", especially when she considers how badly these people dress if their goal is fitting in in London.
Her clothes are decades out of fashion and she can do better than they have with their literal golden money.
...It's a shame, really, that the coins apparently have anti-tampering measures. Gold's expensive.