A possible candidate?

• There was no specification to which Kwon the number refers to. Ji Yeon was conceived on the island while Jacob was alive.
• Sun and Jin could not have had Ji Yeon unless they were brought to the island because Jin was sterile. The purpose of their arrival could have been to conceive Ji Yeon, a candidate.
• Both Jin and Sun were touched by Jacob simultaneously, therefore none of them is a candidate, but their daughter.

• Nobody leaves the Island unless Jacob let them go. Sun was allowed to leave the Island because it was a way to protect her and her daughter from the "time out of joint" situation that was coming. All the others "Oceanic 6" did also leave the Island to be protected, as they were candidates.
• Ji Yeon made Jin the candidate because Sun couldn't be as she became a mother, like Kate, whose name was crossed out after she became Aaron's foster mother.

Ji Yeon Kwon is special, like Aaron?

• She is special because Jin cannot have children, Jacob made Sun pregnant because the Island needs more islanders. Also she could mean something to the island like having special powers like Miles.
• Ji-Yeon was marked special in some way (probably vaccination) by the doctor. The doctor said he was not her normal doctor, that her regular doctor was at a convention. The doctor is employed by the Others. She, along with Aaron will be important later in Season 6.

Unclassified

• Mrs. Paik and Woo-Jung Paik are taking care of Ji Yeon, as they were when Sun-Hwa Kwon was away from home.