Nicki is the mother of Jenny Jagielski who she abandoned for the first 8 months of her life. After returning to Tree Hill has had to fight with Jenny's father Jake to see her daughter and Jake's girlfriend Peyton Sawyer.
Nicki was first introduced in a bar where she met Lucas Scott and had a one night stand with him shortly after he broke up with Peyton and Brooke. Nicki shows up at Jake's house and announces that she wants to be a part of Jenny's life. Nicki bids on Jake at the "Boy-Toy" auction, winning against Peyton. Jake is angry that he had to raise Jenny alone and Nicki was no where to be found for the past 8 months. Nicki says that she felt horrible about it, but she wasn't sure if she would be a good mom and she got scared because all her friends were heading off to college. Nicki tells Jake that she will be a part of Jenny's life, with him or without him. After not being invited to the party that Haley was throwing at Nathan's apartment, Brooke went to a bar and met Nicki. They showed up at Nathan's apartment and Peyton, Nicki and Brooke were constantly fighting with each other. Nicki started a fight with Peyton and destroyed Nathan's apartment which caused Nathan to be arrested. Nicki kidnapped Jenny from Peyton and Brooke when they were in the shopping centre, Jake got Jenny back and fled Tree Hill with Jenny. She tried to use Brooke to find out where he was but was fooled into going to Seattle while he was actually in Savannah.