Mary Newhouse was one of the contestants of "Everlasting" who vied for the chance to be with Adam Cromwell. She was a single mother who was also bipolar and had come from an abusive relationship with her ex-husband—a claim that granted her full custody of their child.
Mary was among the girls in "Limo Three" that Rachel Goldberg would produce in the coming weeks for the show as "her girls". According to Quinn, Shia had tried and failed to woo Anna for the show, but Rachel managed to close the deal with her.
Tired of Mary being reserved, Shia decided to take matters into her own hands after finding out from Dr. Wagerstein about her mood stabilizers. Shia turned off the surveillance in Mary's room and switched out her bipolar medication. Because of this, Mary's attitude changed and she also began drinking alcohol again.
After making a heartfelt invitation video, explaining her past with her abusive ex-husband, Mary was chosen by Adam for the next family date. Mary's daughter, sister, and her sister's children came to visit some time after.
In an effort to push Mary and Adam closer together, Quinn and Rachel decided to invite her ex-husband Kirk onto the show to allow Mary to "confront her abuser", but things turned violent and a fight involving Kirk, Adam, and even Jeremy broke out.
Later, Mary, who was confident that she had won Adam over, confronted a restrained Kirk in a nearby trailer. As she told him how much better off she was without him, Kirk told her how pathetic and naive she was to believe that the show was real and forced her to see his abuse in a different light, telling her that she had begged him to hit her, horrifying Mary. Kirk told her that her "illness" would affect their daughter and that Lily would be better off without her.
After the encounter with Kirk, Mary's family left and she bade them a tearful farewell. Shortly after, Mary went to the roof of the mansion to attempt to commit suicide. Rachel tried to talk her down, but she ultimately let herself drop from the building, even telling Rachel to join her. Quinn rushed to her body that fell by the pool and found blood at the back of her head.
While her suicide was initially kept from the contestants, it was hard to when it became evident that there were no cameras to film a possibly staged drama. The following morning, Adam told the girls of her death.
Her passing temporarily shut down the show while the lawyers tried to stay ahead of any potential charges, which Mary's ex-husband Kirk later did. Shia was struck with guilt for switching out her meds, enough to confess to even Rachel and Quinn, though she still partly blamed Rachel for bringing Kirk—whom she believes pushed her over the edge—onto the show.
When the toxicology report on Mary revealed that she was off her meds and had been drinking again, Quinn knew that they were all at risk, and that the show could get cut because of Shia's doing. In a desperate attempt to save all of their jobs and prevent Kirk from getting money off of Mary's death, Rachel made a fake suicide note where she claimed that she was the one who invited Kirk onto the show, and that she committed suicide to get herself and Lily away from him. Mary's sister, Louise, realized that the note was fake, but still agreed to read it on camera because Kirk was trying to get custody of Lily Belle.