|Dates||???? - 2017 (died during child birth)|
|Location||North Cove, Washington|
|Episode(s)|| 12.08 LOTUS|
12.13 Family Feud
12.17 The British Invasion
12.19 The Future
12.23 All Along the Watchtower
Kelly Kline was an aide to President Jefferson Rooney. At some point in time, the two began an intimate relationship after the death of Rooney's wife. After Rooney is possessed by Lucifer, she becomes pregnant with his child -- a Nephilim.
After the sudden death of a Secret Service agent, Kelly reminds the newly Lucifer-inhabited President Jefferson Rooney that he should lead them in prayer, like he always does every morning. When Lucifer obliges, Kelly and the rest of the staff get on their knees and pray along.
The next day after a briefing, Kelly informs Lucifer that he (as Jefferson Rooney) is officially the most popular sitting president, according to a recent poll. While Lucifer is impressed by the news, Kelly tells the Secret Service agent watching them to take a break. When Lucifer asks Kelly if there was anything else, the two end up having sex. Post-coital, Lucifer learns from Kelly that they have been having an affair for sometime now, with Kelly telling him how she hopes one day they could be a couple in public. She wants for them someday to get married and have a child, remarking that Jefferson would make a good father. Later that night, after having sex once again, Kelly remarks that something was different, that she feels something has changed.
After finding that a Nephilim has come into existence, Crowley is able to learn of Kelly's relationship with President Rooney through his contacts. As Kelly finds out she has become pregnant, Crowley teleports to the presidential retreat and whisks Kelly away back to Sam and Dean's motel room. They try to explain the situation to her, which she finds hard to believe. They tell her that they know of her pregnancy and that the child is Lucifer's. When she still does not believe what she is being told, Castiel tells her that her child is an abomination and has her place her hand on a Bible, which is set aflame upon her touching it. Kelly, finally believing what is going on, agrees to help them lure Lucifer to the motel room in order to remove him from President Rooney.
As Lucifer arrives, he has the Secret Service go through and sweep the motel. When an agent finds Castiel in the closet, the angel touches his head and tells him there is no one in the room other than Kelly, and to wait in the car. After being given the all-clear Lucifer enters the motel room, where Kelly tells him that she can't keep their child. Angry, Lucifer begins choking Kelly until Sam bursts into the room and uses the hyperbolic pulse generator on Lucifer. After Lucifer is expelled President Rooney, Kelly in tears begins calling out to him. Sam and Dean have Castiel take her away while they check on the president. Sometime later, at a diner, Kelly excuses herself to the bathroom, but while Castiel is not looking, she sneaks out the back entrance and calls a taxi. By the time Castiel realizes she is gone, Kelly is already down the road. She calls him from the cab to tell him that she can't get rid of the baby. She says she can feel it inside of her and that she is still its mother, before hanging up.
At a diner in Coeur d'Alene, Idaho, Kelly orders an orange juice from a waitress, who talks to her about her pregnancy. After taking Kelly's order, the waitress walks away from her booth, her eyes glow an angelic blue.
Later that night, Kelly is walking down a road. She looks back to see a man walking behind her, prompting her to begin walking faster and duck behind a building. She looks around the corner to see nothing, but as she sighs in relief she sees the man. She runs into an alley only to see the waitress blocking her escape with an angel blade drawn. Dagon quickly appears and orders the angels to get away from Kelly, when the male angel disregards her, and attempts to attack her, Dagon kills the two angels with ease. After being taken to safety a startled Kelly questions what happened, Dagon explains how she is a demon and those were angels trying to kill her, telling her that she has come to help her and her unborn child and how he could save everyone. Convincing Kelly to take Dagon as her protector.