you yourself said:

>After beating her in battle, say says "Yes, a mere half year ago I was a Black Belt! Quite the transformation, wouldn't you say?"

I assume this is all she says as you put a full quote in the text of youre post and trainers dont talk much after getting whooped. this does not really imply transgenderism. Its just a vocational change. unless it literally says she's trans or unless the creators confirm this theory, its just that, a theory.