Danielle Rousseau developed several relationships over the course of the series.


Alex and Danielle
First Episode: "Dead Is Dead"
Origin: Danielle gave birth to Alex on the Island
Since Then: Isolation following Alex's kidnapping drove Danielle insane. When she trapped Sayid, she interrogated him about Alex's whereabouts. She later kidnapped Aaron, hoping to exchange him for Alex. Shortly after she helped the survivors defend themselves from an Other attack, Alex and Danielle finally reunited. They both died shortly afterward.
3x22 ReunitedAtLast


Ben and Danielle
First Episode: "Dead Is Dead"
Origin: Ben kidnapped Alex when Widmore ordered him to kill Danielle.
Since Then: Danielle found Ben in one of her traps years later. She did not reveal whether she recognized him, be she was certain that he was one of the Others. She shot him with a crossbow and turned him over to Sayid for interrogation. When she reunited with Alex some weeks later, she struck Ben to shut him up. In the flash sideways, the two seemed to share a romantic attraction.
4x01 ShutUpBenLines


Danielle and Robert
First Episode: "This Place Is Death"
Origin: In 1988, Danielle and Robert were part of the same science expedition team that ended up stranded on the island. She was 7 months pregnant at the time, and the father was Robert
Since Then: Soon after arriving on the island, they were attacked by the Smoke Monster on their way to the radio tower. While trying to save Montand, Robert and other members of the team went into the Temple while Danielle stayed behind. When Robert emerged, alive, Danielle was convinced that he was "infected" with some sort of "sickness", in which she was convinced he wasn't the man she knew. Robert tried to convince her that he was indeed "Robert" to an armed Danielle. She lowered her rifle down momentarily, but when Robert surprisingly tried to shoot her with his rifle it did not fire, as it had it's firing pin removed. Danielle immediately shot him dead. Danielle survived on the island for 16 years and gave birth to Alex, who would soon by kidnapped by Ben.


Danielle and Sayid
First Episode: "Solitary"
Origin: Sayid walked into one of Danielle's traps.
Since Then: Danielle tortured and interrogated Sayid, thinking him an Other. Even when he convinced her she was wrong, she tried to keep him against his will so she could touch him. She visited his camp after whispers warned her about the Others, and only talked when she saw him. She asked for him again later, when she trapped an Other. She helped Sayid, Kate and Locke navigate the island during their trip to the Barracks to rescue Jack. The two met last after Sayid entered the Barracks after while Locke controlled them. She held a gun to him, but she told him it was "nothing personal".
1x09 AStoryOfInsanity