Snape's Sentimental Sin

Lynx Black, twin to youthful Sirius Black, is just starting her first year at Hogwarts. She makes many good friends, and is accepted into the secret pranking group known as the "Marauders". She hates that they pick on Severus Snape, and often defends him against the three- once, going as far as making an enemy of them, in sorts. But when she's accidentally cast forward in time, the only teacher that will take her... is Snape.