She was very popular with the boys at school, attracting the attention of both George McFly and Biff Tannen. Her two best friends are Betty and Babs. She originally met future husband George in 1955 when her father almost ran him over with his car. Lorraine and George married and had 3 kids, Dave, Linda and Marty. By 1985 she was depressed at how her husband couldn't stand up for her and also smoke and drank a lot. She would always tell her children not to park in cars with boys, since she never did that when she was their age.
Her life changed in 1955 when "Calvin Klein" showed up in town. Unaware it was her future son Marty, who had travelled back in time in his DeLorean time machine and had accidentally interfered with her first meeting with George, she developed a crush on him. Marty knew he had to get his parents together to prevent himself from being erased from existence and so set up a plan where he would pretend to park in a car with Lorraine, and the wimpy George would "rescue" her from him. Unfortuantely, bully Biff Tannen showed up instead and tried to force his affection on Lorraine. George arrived and rescued her by punching Biff. Lorraine fell in love with the newly-confident George and by 1985 she is much healthier and happier than she had been in the original 1985.
We also see a third version of Lorraine in a third 1985. In this timeline Biff had received a sports almanac in 1955 from his 2015 self and had become rich. Biff had murdered George in 1973, although Lorraine did not know it was Biff. Biff and Lorraine married soon afterwards and by 1985 she was trapped in a loveless, abusive marriage. Luckily, Marty and Doc Brown went back to 1955 and stopped Biff from using the almanac, so the timeline went back to normal.
As a teenager, she smoked, drank liquor, sat in parked cars with boys and cheated on tests (in a scene that was edited out of the movie), proving she wasn't as sweet and innocent as children thought she was. As an adult, Lorraine likes playing tennis with her husband and gossiping with her friends.