Nikki Chisom is the abusive former partner of HART paramedic Jess Cranham. In late 2015, Dixie started to have suspicions that Nikki was abusing Jess and her daughter, Olivia. This was later confirmed in 2016, when she injured Jess on Olivia's birthday. When they were admitted to the ED, Olivia revealed to Jess that it was in fact Nikki who hurt her. Meanwhile, Nikki asked where they'd gone and discovered they'd gone home, and decided to beat them to it. When Jess and Dixie arrived with Olivia, Nikki grabbed her, but quickly angered and threw the lit birthday cake across the room. It started a fire, and although Jess and Olivia managed to get out safely, Nikki suffered severe burns. Back at the ED, Jess broke up with Nikki, saying she can't forgive what she did to Olivia.