Origin: Cindy and Libby were stranded together for 48 days after the crash of Oceanic Flight 815.
Since Then: They spent over forty days together, in which they did many things. They fished together, made decisions together, moved constantly around the island together. They were together when they found the Arrow Station and when Jin washed ashore. They're both kind and sweet and didn't agree to what Ana Lucia was doing to Nathan.
Origin: Following the crash of Flight 815, Mr. Eko asked Cindy to look after the children.
Since Then: Afterwards, she is seen with Libby comforting the children on the first night when the first three Tailies are taken. Once in the captivity of the Others, she is portrayed as the sole caretaker of Zach and Emma, and remains so for at least three years, when she is next seen at the Temple, as well during the Others' exodus with the Man In Black.