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Ian Thomas is born to Mr. and Mrs. Thomas.
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Ezra Fitz is born to Mr. and Mrs. Fitz.
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Melissa Hastings is born to Peter and Veronica Hastings.
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Wren Kingston is born to Mr. and Mrs. Kingston.
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Jason Day-Dilaurentis is born to Kenneth and Jessica Day-Dilaurentis.
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Eric Kahn is born to Bill and Eleanor Kahn.
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Toby Cavanaugh is born to Daniel and Marion Cavanaugh.
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Jenna Marshall is born to Mr. and Mrs. Marshall.
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Emily Fields is born to Wayne and Pamela Fields.
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Hanna Marin is born to Tom and Ashley Marin.
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Maya St. Germain is born to Mr. and Mrs. St. Germain.
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Spencer Hastings is born to Peter and Veronica Hastings.
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Alison and Courtney Day-Dilaurentis are born to Peter Hastings and Jessica Day-Dilaurentis.
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Aria Montgomery is born to Byron and Ella Montgomery.
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Grace and Noel Kahn are born to Bill and Eleanor Kahn.
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Mona Vanderwaal is born to Mr. and Mrs. Vanderwaal.
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Mike Montgomery is born to Byron and Ella Montgomery.
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Courtney is hospitalized at the Radley due to getting diagnosed with paranoid schizophrenia after her twin sister Alison’s constant manipulation and lies caused her to act out and seem violent and unstable. In the end it was Alison’s choice whether or not to send Courtney away, and since it was her plan all along to get rid of her, Courtney is sent away sometime between January and June in 2004 before her 10th birthday.
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The DiLaurentis family moves from Stamford, Connecticut after Courtney’s Hospitalization and changes their last name from Day-Dilaurentis to DiLaurentis in order to start over and hide Courtney from their new friends and neighbors.
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Mrs. Marshall marries Mr. Cavanaugh, and moves to Rosewood with her daughter Jenna.
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Emily, Spencer, Grace, Hanna, Aria, and Alison all find out about Rosewood Day’s infamous Time Capsule game starting the next day. When Ian suggests to Alison that someone might steal her piece of the Time Capsule flag once she’s found it, the same plan begins forming in all the Liars' minds: they are going to steal the piece from Alison.
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As Emily, Spencer, Grace, Hanna, and Aria assemble in Alison’s backyard getting ready to steal her piece of the flag, inside, Courtney realizes she has the perfect opportunity to take her sister's spot and trick their parents. Seizing the opportunity, Courtney struts outside wearing her sister's ring, shoes and matching clothes. She begins a conversation with the Liars, and when it’s time for Courtney to leave for the Preserve, Mrs. DiLaurentis mistakes her for her sister.
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The Saturday after the twin swap, Courtney goes to the Rosewood Day Charity Drive where she befriends Emily, Spencer, Grace, Hanna, and Aria.
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"The Jenna Thing" accident happens.
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Toby leaves Rosewood and goes to a juvenile facility. The girls go camping in the Poconos and Courtney gives them their friendship bracelets for The Jenna Thing.
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Hanna and Courtney go to Annapolis to see Hanna's dad.
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Ian kisses Spencer after Courtney promises to kiss him if he kisses Spencer.
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Aria records a casual home video of a talk show featuring Courtney, Spencer, Hanna, Grace, Emily and Ian. This footage later emerges during Ian’s trial.
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Aria and Courtney catch Byron cheating.
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Emily kisses Courtney.
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Spencer, Emily, Grace, Hanna, and Aria visit Courtney's house to share news about their end-of-seventh-grade sleepover. Unbeknownst to them, they meet the real Alison who’s home visiting.