i agree with what the other anon said, but the reason why i said it is executed well, i wasn't talking about the development to become that thing, but how that character is written as one.
She desired to learn it, not to "prove" women can fight just like guys do, but because she wanted to protect her friend/love interest. She became so obsessed with the idea of being a knight, that she was willing to die for him. Her outfit during the training was perfectly well gender neutral, not a dress or skirt because "i am a girl and i have to show it", but also not butch-lesbian type with a shorter haircut.
That's what i like about her, the development thing, well, as the other anon said, in anime that is common place, so i never minded(not to mention pearl is still stronger than her, so that complain doesn't work anyway)