Lily is a Muggleborn witch, an Outsider and is married to James Potter.
Lily grew up in a Muggle neighbourhood with only her sister Petunia and childhood friend Severus Snape for company. She went to Hogwarts at the age of eleven and met James Potter, Sirius Black, Remus Lupin and Peter Pettigrew as well as fellow Outsiders Alice and Frank Longbottom.
In their later school years, James persued Lily, while Severus drifted further away in favour of Lord Voldemort and his followers. After leaving school, she and James were married, and while Severus remained on the side of Voldemort, she considered their friendship over.
James and Lily were married about a year after leaving Hogwarts even as Voldemort's power was growing. They joined the Order of the Phoenix under Albus Dumbledore's leadership and lost several friends to the Death Eaters' regime. Lily became pregnant late in 1979, but her happiness was soon marred by the Prophecy that marked her son as a potential target of the Dark Lord. She and James went into hiding with their son Harry, who was born in July of 1980, using a Fidelius Charm with James' friend Peter Pettigrew as the Secret Keeper. Unbeknownst to them, Peter was a spy for Voldemort. On Halloween 1981, Peter took Harry from their home under the pretence of putting him to bed. He took the baby boy to Voldemort, who killed him in cold blood. Distraught, Lily and James contacted Dumbledore, who was also murdered at Voldemort's hand. Out of options and grieving the loss of their son, the Potters went into hiding.
The OutsidersEditLily and James spent the next seventeen years going from place to place, living in flats, motels, rented rooms and occasionally tents or even squatting in abandoned houses or factories. They were always together but had very little extended contact with other families on the run. It was during this time that James taught Lily to be an Animagus in the form of an ocelot.They were eventually contacted by Kingsley Shacklebolt who helped James to organise a house where they could live in secret with other Outsiders. Lily, who had previously taken whatever casual work she could get,got a part-time job sorting mail in a Muggle post office.
She met Severus again when he spotted her coming home from work. She could never forgive him for delivering the Prophecy that got her son killed into Voldemort's hands, but she agreed to reply to messages from him in return for his help on the inside.