*CUT TO THE CHASE*
NOTE: This spoiler was submitted by Jeremy
2002 - Christine "Lady Bird" McPherson (Saoirse Ronan) and her mother Marion (Laurie Metcalf) are driving back to their home in Sacramento, CA. after a tour of CA colleges. As Lady Bird is about to start her senior year of school, she is already thinking ahead of applying to schools away from California, particularly in New York. She and Marion argue over the issue, and Lady Bird throws herself out of the moving car to avoid hearing her mother talk, resulting in her having a broken arm.
Lady Bird attends a Catholic school and is a long-time friend with Julie Steffans (Beanie Feldstein). The two of them mess around at the market where Lady Bird's brother Miguel (Jordan Rodrigues) works, plus Miguel's girlfriend Shelly (Marielle Scott), who also lives with the McPhersons.
Lady Bird and Julie try out for the school's production of "Merrily We Roll Along". Lady Bird develops a crush on a boy named Danny O'Neill (Lucas Hedges), and the two of them start to date.. They lay in the grass at night and look up at the stars, picking one out and naming it.
Over Thanksgiving weekend, Lady Bird joins Julie, Danny, and another friend as they smoke weed for the first time. They eat leftovers and laugh when Marion sees them. Later on, the students put on their show. At an afterparty, Lady Bird finds Danny kissing another boy in the bathroom stall. She later confronts him over it, and he breaks down crying because he can't bring himself to admit that he's gay to others. Lady Bird hugs him.
Lady Bird starts to make friends with a popular girl named Jenna Walton (Odeya Rush). She gets on Jenna's good side when they pull a prank on a teacher by putting a "Just married to Jesus" sign on her car. Later, the two meet up with another student named Kyle Scheible (Timothee Chalamet), who is in a band. They meet up with Kyle and other friends in a parking lot where they like to hang out. Lady Bird and Kyle later hook up at a party at Jenna's house. However, Lady Bird being friends with Jenna causes a strain on her friendship with Julie.
Lady Bird hangs out at Kyle's house after she decides she is ready to have sex. They do so and he finishes quickly before he tells her that he was never a virgin as he had previously suggested to her. Lady Bird is angry at Kyle for lying, but he doesn't seem too concerned about it. Marion goes to pick her up, and Lady Bird starts crying. Marion then decides to take Lady Bird out.
The two go to the mall to shop for prom dresses, and Lady Bird becomes upset when Marion criticizes the dresses she tries on. She tells her mom she wants her to tell her she’s pretty and that she likes her (not just loves). Marion tells her that she’s always encouraged her to be the best version of herself, and Lady Bird worries this is her best.
Lady Bird checks the mail for college letters. She is disappointed at being rejected for most colleges due to her average-to-poor grades, but she becomes excited when she is told she is on the waiting list for a New York college.
Kyle picks Lady Bird up on prom night with Jenna and her boyfriend. They decide they want to ditch prom altogether and go somewhere else. Lady Bird tells Kyle to drop her off at Julie’s house. When she gets there, Lady Bird and Julie make up and head to prom together. Julie also tells Lady Bird she may not see her for the summer because she’s going to stay with her father.
Lady Bird and her friends graduate. While at lunch with her family, Danny passes them and accidentally lets it slip that Lady Bird is on a waiting list for the NY school, despite her telling her family she was going to University of Davis to stay close to home. Marion gets very upset and stops talking to Lady Bird for the summer, even as she tries to explain herself.
Come September, Lady Bird bids her family and friends farewell. Her parents take her to the airport, and Marion is still not talking to her. Larry takes Lady Bird to the gate as Marion goes to park, but she then tries to make it to the departures entrance. She runs tearfully into Larry’s arm, assuring her that Lady Bird will return.
At college, Lady Bird goes to a party where she gets very drunk. She meets a guy and introduces herself as Christine. They start to hook up but Lady Bird pukes and winds up in the hospital.
Lady Bird wakes up and leaves the hospital. She walks back toward her dorm through the city and then stops to call home. It goes straight to voicemail, so she leaves a message for Marion saying she should have told her more how much she loves her.