Episode 3x2, The Glass Ballerina
Jin wants to go back to the main beach, but Sun thinks they should take the boat around a mountain to start another signal fire as Sayid said. Jin and Sun argue. Sun later apologizes for disagreeing with Jin in front of Sayid. Jin says she should not disagree with him at all.They go ashore and Sun figures out that Sayid is lying. Sayid confesses his plan to build the big fire because he thinks Jack and the others have been captured. He hopes the Others will see the fire and send a scouting team. Sayid plans to kill all but two and then use one to get the other to talk.
Jin tells Sun that he understands more English than she thinks he does and that he knows she betrayed him.
Sayid and Jin make Sun go back to the boat. The Others board the boat and Sun gets a gun. Colleen goes down into the cabin and says that Sun will not shoot her because she's not a killer. Sun shoots, then escapes off the boat and swims to Jin.
Episode 3x11, Enter 77
Sawyer bets that he can win ping pong against any of them and if he does he wants his stash back. Sun suggests that if he loses he give up nicknames for a week. Sawyer loses.Episode 3x12, Par Avion
Sun helps Claire and Jin try to catch a bird for Claire to attach a message to. Sun also helps Claire care for Aaron.Episode 3x14, Expose
Charlie tells Sun that it was him who had kidnapped her and that it was Sawyer's idea. Sun later confronts Sawyer and slaps him.Episode 3x16, One of Us
Sun makes it clear that she does not trust Juliet.Episode 3x18, D.O.C.
Sun asks Kate if she thinks Jack is working with the Others and Kate says no, but she tells Sun that Juliet said that they wanted Claire's baby for research. Sun confronts Juliet to ask what happens to pregnant women on the island. Juliet tells her that they all die.In the middle of the night, Juliet takes Sun to the medical station so that she can do an ultrasound to determine when the baby was conceived. Sun says that if the baby was conceived off the island it is not Jin's baby, so either way she loses.
Juliet says that the baby was conceived about 53 days ago, so the baby was conceived on the island.
Sun begins to cry and Juliet goes to console her, but Sun is happy because the baby is Jin's. She tells Juliet that she gave her good news.
Episode 3x20, The Man Behind the Curtain
Sun doesn't think Jack would do anything to hurt them and she thinks that Juliet is a good person. She tells this to the group as Sayid tries to convince them otherwise. Sawyer plays the recording of Juliet talking about Sun's baby.Episode 3x21, Greatest Hits
After he realizes that something is going on, Sun admits to Jin that she saw their baby on an ultrasound and the baby is healthy.Episode 3x22, Through the Looking Glass
Sun is worried when they only hear two explosions from the beach camp. She and Rose comfort each other.Later, Sun is overjoyed when she hears that Jin is all right.
