Sun didn't end up killing Ben when she found out Jin was alive, and she instead traveled with him to the Island in 2007. Widmore ended up coming to the Island as well via a submarine, and he retrieved Sun's camera from her crashed plane. He later imprisoned Sun along with Jin and several followers of the Man in Black in cages, therefore, he was ignoring their earlier off-island partnership. Widmore was later killed by Ben at the Barracks while Sun died with her husband Jin on Widmore's submarine.