"What do you need boy robes for?" inquires Madam Malkins.
"I'm sometimes a boy," the girl explains.
"What?"
"Look—"
"Probably?" he shrugs. "It's not guaranteed, I might be Ravenclaw? I'm probably not really cunning, though, or – uh, Gryffindorish?"
"I don't really know which is right, Professor Flitwick didn't want to tell me much about the Houses."
"Gryffindors are brave and loyal, Ravenclaws are book-smart and curious, Hufflepuffs are hard-working and form tight groups, Slytherins are ambitious and cunning?"
And then a young girl is at the door to the compartment, looking a bit nervous but holding her head high.
"Uh. H-hi."
In she comes! She has some luggage with her which she puts under the chair and then she looks around a bit and after a moment she sits.
"I think I'm gonna be a Slytherin, she thinks she's gonna be a Ravenclaw, he thinks he's gonna be a Hufflepuff, we need a Gryffindor to complete the set."