In Terminator: The Sarah Connor Chronicles season 2 episode 17 "Ourselves Alone" Derek and Jesse are shooting apples. When they are doing this Derek says that his Judgment Day is 21st April 2011. After that he asks Jesse what is her Judgment Day is, but she didn't give an answer to Derek.
So what is the reason for Jesse to hide her Judgment day from Derek and why does she keep that as a secret?