The Short Version:
Olivia is a 5th Year Slytherin, Pureblood. She was raised as a muggle by her parents until her first year at Hogwarts when they told her about her history. She now hates muggles because of that experience. She can be elitist when she wants to, but usually she values character above everything else. She thinks that teenagers should be very proper, as she was raised. She values intelligence and class above everything else.
( The Long Version )Basically she needs friends, enemies, anything! Backstory away!