The all important disclaimer - it ain't mine
They heard her before they saw her as they waited in the kitchen at Grimmauld Place, for this emergency meeting Albus had called. Ron fidgeted, Hermione gripped her book tight, Sirius glared at Snape who ignored him, with an odd expression across his sallow face, Molly stirred a pot, Mad Eye stared through the walls, and Harry held himself very, very still.
When the door clicked open Mrs. Black began to yell and curse but, instead of fleeing the dead woman's vitriol the eager listeners heard the footsteps cease.
"Now then," the voice – young, female – said with half a smile, "That's no way to greet a guest."
To considerable surprise, the portrait seemed to quail, "Of course," she whispered. "Of course not, my apologies… please, welcome… welcome to my home. I did not know of what power I spoke, just presumed…"
"Well," said the young woman. "Don't presume."
Albus said something, perhaps congratulating the girl on her feat, and they walked into the kitchen to a hoard of staring eyes.
She was slight with auburn hair and green eyes, clad in a fuzzy pink jumper and ripped jeans. She didn't smile. They continued to stare. She raised one auburn eyebrow with a poise she had only just acquired.
Perhaps she would have said something had Snape not pushed past Lupin in an uncharacteristic hurry and dashed himself to the ground on first one and then two knees, "Thank you," he whispered, "I'm sorry, I shouldn't have... made such a scene. I'm sorry. But thank you. Thank you."
She crouched down beside him and laid a hand on his shoulder, "For him?" She asked.
"What else?"
"Then I guess I'd better say you're welcome," she said gravely.
And suddenly, quite abashed, they bother rose, with Albus Dumbledore's piercing eyes twinkling down on them.
Lupin glanced from one figure to the other and then up to Dumbledore, "If someone would explain exactly what just happened…"
Dumbledore's eyes twinkled all the more, "Ah, of course, how could I be so remiss?" He smiled, "Friends, fellow order members, this is Willow Rosenburg and she has killed Voldemort."