Faye Donahue is the fiancé to Kyle Holmes and a femme fatale who takes to Frank Gallagher for reasons at first not understood.
In Citizen Carl, she walks into The Alibi Room when Frank is giving his speech about Billy. She catches his attention and the two end up sitting with each other. She asks for help with a boot on her car and Franks offers his assistance.
When he welds the boot off, she offers for them to eat at her place, to which Frank is intrigued to find is her car.
In Debbie Might Be a Prostitute, when she arrives at the Alibi, Kevin Ball asks if if she has a house, and she replies yes. She tells Frank her house is haunted. When she tells Frank of the scotch collection, he tells her he can help.
When they drive up to the house, she gets cold feet but Frank holds her hand. When they enter the house, Franks wants to start in the room with the scotch collection. When walking up the stairs, he sees a picture of Faye at a graduation with a man. She tells him that was right before her life changed forever. When they enter the bedroom, Faye tells him to lay on the bed. She begins to handcuff his hands to the bed. Then she gets on top of him and yells, "Boo."
She walks in later after Frank wakes up from the drugged scotch and asks if he remembers Kyle Holmes. She continues to ask him while Frank is confused. She then tells Frank Kyle was her fiancé and was suppose to married until he ruined it. She gets angrier when Frank continues to be confused by the questions. She then asks him about the summer of 1995. She bring out a TV and plays an old video of a young Frank in court being called the victim of drugs and Kyle Holmes his dealer. Kyle is then sent to jail while Frank is sent to rehab. Faye turns to Frank and tells him Kyle has been rotting in prison for twenty-four years. When Frank calls it a "not me" problem, she is shocked that he really doesn't remember. She then leaves for the hardware store and plays the video on loop.
In Now Leaving Illinois, Faye is later present at Frank’s trial hearing and is pleased that she will get her revenge. However, she is in a state of shock to see when Frank manipulates the judge into only sending him to rehab. As he is escorted out, Frank smiles smugly to Faye in victory.
In Location, Location, Location, Faye later catches up to Frank and tells him that she visited her ex fiancé who told her to let go for a grudge because he wants to kill Frank as soon as he is released. Faye tells Frank that she only wanted to tell him that she’s going back to Puerto Rico and hopes to meet again. With news of her departure Frank immediately squats at her house only to find that he was not the only one that had the idea.
In Gallavich, Liam tricks Frank into borrowing Faye's Mercedes for Ian and Mickey's wedding reception. The two subsequently use Faye's car to go off on their honeymoon.