No, not Batgirl, but a Batman Princess. It makes perfect sense to me. When my three-year old is dressed in her Dora the Explorer shoes, shirt, and jacket, she says "I'm a Dora Princess!" Once she called me a princess simply because I was wearing a hat. "Princess" just means "fancy". Can you be a Batman Princess? Yes, of course. The crafting blogger Donkey's Alright understands this.
Link -via Comics Alliance