Marty McFly’s girlfriend was Jennifer Jane Parker. Jennifer was the world’s fourth and third human time traveler. She was born in the California town of Hill Valley in 1967. Marty’s girlfriend, she met him at Hill Valley High School in 1985, where they both attended.
Jennifer and Marty appeared to be “serious” enough for him to introduce her to his best friend, local inventor Dr. Emmett Brown, who was widely regarded as odd and unusual.
Jennifer had a generally upbeat outlook on life, knowing what to say to Marty when he needed cheering up and fantasizing about the wonderful life she might have in the future.
Jennifer assisted Marty in covering for him when he was late for class on October 25, 1985, but she was caught herself. Mr. Strickland gave her a tardy slip, but her disciplinary record had not yet caught up to Marty’s notorious “four [tardies] in a row.” Jennifer accompanied Marty to the Battle of the Bands audition after school, and after The Pinheads were rejected, she consoled him by reminding him that one rejection was not the end of the world, and that if he put his mind to it, he could achieve anything – which was also a Doc saying.
Jennifer and Marty had planned to go camping by the lake that weekend, but when they kissed in Courthouse Square, they were interrupted by the Clock Tower Lady and then her father. Marty vowed to call Jennifer as she prepared to depart. Jennifer was going to her grandmother’s house that evening, so she put down her grandmother’s phone number (555-4823) on the back of a “Save the Clock Tower” flier, along with the words “I love you!” Marty retained the flyer in his pocket as a result, and it was still in his possession when he got stuck in 1955.
On Friday night, Jennifer attempted to phone Marty again but was sent to Marty’s sister Linda, who made it clear to Marty that she was not his “answering service.” Lorraine from the previous timeline reacted angrily to this, saying she didn’t agree of the Sadie Hawkins method and that she doesn’t appreciate girls who call up boys. Lorraine’s attitude toward Jennifer had substantially improved in the second timeline, and she welcomed Jennifer dating Marty, likely making the adjustment to accepting Jennifer as her future daughter-in-law easier.
Jennifer arrived at the McFly house the next morning in the second timeline, unknowing that Marty had spent a week in 1955 since she last saw him. Because of the adjustments Marty had made in the past, he now possessed a truck, and Jennifer had come for a ride. Doc appeared in his DeLorean time machine just as they were ready to leave. Jennifer went on a trip “to the future” with Marty and Doc.