Could give her an unfitting nameIf she had a very girly name, then she would insist that everyone would call her by a nickname (for example, she could be called Beatrice but called Trish. Clarice but called Clair. Tiffany but called Tiff). Most of her friends would be oblivious of her real name which would give them a good reason to laugh when they finally figure it out.
The "That's your name" moment is a classic that's handy to use but it's a very common plot element associated with tomboy girls so don't use it if you're trying to avoid cliches.