Disclaimer: (dramatic sigh) Oh, 'tis a pitiful thing. As many wishes as I may make, Harry Potter and his friends will always belong to J.K. Rowling. I own nothing (weeping).
Ron gasped, Ginny giggled, Percy's eyes widened, and Fred and George's jaws dropped to the floor.
Dumbledore smiled, amused, "Care to elaborate?"
"I am Rose Weasley, eldest child of Ron and Hermione Weasley," she grinned at the looks on her parents' faces.
Ron was shock still, gaping at his apparent daughter, and Hermione was blushing and stuttering.
Fred smirked at George, "You owe me five Sickles."
"You bet on us?! Well, at least George didn't think we'd get together," Ron muttered, embarrassed.
"No, actually," George said, dropping the money into his twin's hand, "I bet that your first child would be a boy, while Forge said it would be a girl. I lost, obviously."
Hermione glare at them, then smiled at Rose, "Tell us about yourself, sweetie."
"Well, I'm fourteen," Rose said, "I have a younger brother named Hugo, and I play Chaser on the Gryffindor House team, along with my cousins Lily and Dominique."
"My turn!" Albus sang, "My name is Albus Severus Potter."
It was Harry's turn to pale.
"I have a child," he stammered.
Dumbledore's blue eyes were filled with tears, "I'm touched that you would name your son after me, Harry."
"It's nothing, Professor," Harry rubbed the back of his neck , his cheeks flushed, "Speaking of names, why'd I name you after that slimy git?"
Snape was wondering the same thing.
Albus smiled mysteriously, "You'll find out in, say, three years. Anyway, I have an older brother named James Sirius-"
McGonagall nearly fainted, she had had enough trouble with James Potter and Sirius Black, but a James Sirius with Potter blood... She didn't know if she would survive another generation.
"-and a younger sister named Lily Luna," Albus continued, "Oh! And I'm the middle child of Harry and Ginny Potter."