Katherine Jordan DeLong (also known by the alias Jordan Richards) is Emily Fields ex-girlfriend. They broke up because Jordan did not want to get her sent to jail because she was a thief who was wanted by the FBI. She ran away from the boat and Emily before the FBI can catch her, though but she promises Emily that they will be together. She appeared in Burned.
Emily and Jordan meet in Burned when Emily catches her hiding in her opened room during the school's eco cruise, though Emily and her friends have seen her sneaking around the boat since they boarded. Jordan is referred to as "Ghost Girl" until she introduces herself (using her alias) to Emily.
Emily and 'Jordan' (Katherine) stay in contact secretly through twitter. In Deadly, A revealed to the police that Emily was keeping in contact with Katherine. She was charged with aiding and abetting, however her charges were dropped in return for information about A and Ali. At the end of Deadly, Katherine is caught by the FBI in the carribean. She is mad at Emily for dancing with another girl.
In Toxic it is revealed that she is in jail and asks for Emily to come and see her. This is the last time where the two of them see each-other, because the next day, Emily finds out that Jordan was murdered by a girl named Robin who was most likely put to kill Jordan by Real Ali.
Jordan has large green eyes, full lips, and thick, long, dark hair. When she meets Emily she is wearing a white eyelet dress and a velvet headband. She also wore flats that had a pretty trimmed bow on them.
Emily is initially frightened by the prospect that Jordan/Katherine has broken into her room. However, once Emily learns she is a stowaway, she offers for Katherine to bunk with her, since her roommate, Erin may not be staying with her much. Over time, Emily discovered that Jordan/Katherine and herself shared similarities, as Jordan once had a friend that she loved in a more-than-friends way, but she didn't return her feelings. Instead, her friend used these feelings to manipulate Jordan in doing things, which landed her where she is now, running from the cops. Slowly, they develop feelings for one another, and one night on the cruise ship, they kiss. In the end, Jordan and Emily have to part ways, since A revealed Jordan's whereabouts to the FBI, but they stay in touch. By the end of "Deadly", it is clear that Jordan is currently mad at Emily for dancing with another girl at a gay bar, thinking it meant something more than just fun.