Carrie is introduced as the nurse who looked after Mary King when she was dying, late wife of Tom King, and mother of Tom's teenage daughter, Scarlett. It was revealed that Tom had written to Scarlett on an annual basis, but Carrie returned the letters, disappointed that Tom wasn't not prepared to be a full-time father. She did, however, allow Tom to pay for Scarlett to attend a private school. After Tom's death, Carrie appeared at the funeral and the will reading where the Kings learned about their secret sister. He left Scarlett a quarter share of Home Farm and 10 percent share of King and Sons. The King brothers all reacted differently to Carrie, although they were united in their disgust at their father cheating on their mother whilst she was dying.
Matthew King wanted rid of Carrie and Scarlett and tried to buy Scarlett's shares. Carl King also wanted to get rid of Carrie - it was later revealed that they had had a brief fling when Carl was a teenager. The dates were vague but they discussed how she took his virginity at sixteen and later rejected him, telling him it meant "nothing". Carrie said she hadn't meant to hurt him but that they should forget it as it was ancient history. Carl was hurt and stormed off. Jimmy, being the most kind-hearted of the three, offered Carrie an olive branch so he could get to know his young sister. Scarlett refused to sell her shares and insisted that she and Carrie move to the village - gazumping Matthew by buying Mill Brook Cottage - a property he intended to turn into flats.
When the King brothers faced prison sentences, Jimmy suggested Carrie be named a director of King and Sons so that she could run the business in their absence. Matthew was against it, but Carl agreed and Carrie accepted, becoming part of King and Sons. The Kings were cleared but Carrie kept an eye on the business. She helped the Kings "persuade" Rosemary King to move out of Home Farm by telling her that Carl had confessed to murdering Tom and Rosemary confessed that she had bribed Hari Prasad to give a false statement to the police. The latter was disastrous when Rosemary fell over a balcony, trying to call the police. Matthew forced her to sell and Carrie was welcomed into the family for helping get rid of Rosemary.
Carrie and Kelly Windsor were instant enemies. Carrie took a dislike to Kelly because of Kelly's relationships with Jimmy and Scarlett. Carrie didn't approve of either but was ignored. She was worried about Kelly leading Scarlett astray, especially after she found a leaflet from an abortion clinic in Scarlett's coat pocket.
It was later revealed that Carrie is Lexi's mother, not her sister. Carrie gave birth to Lexi when she was 14. She confided in Jimmy, who told Kelly. Carrie knew that Kelly had had an abortion but Kelly warned Carrie that if she told Jimmy about the abortion, Kelly would tell Scarlett that Lexi was actually her half-sister, not her aunt.
After declaring her love to Jimmy, which she soon realised was unreciprocated, Carrie ended their affair and received a job offer from an ex-boyfriend, Nick Baine. The job was in Canada and she decided to take it. She and Nick also rekindled their relationship. She left Jimmy and Lexi in charge of Scarlett and emigrated in February 2008.
Carrie has been mentioned and gets in touch occasionally since she left. Scarlett spent the summer with her as Jimmy wanted to keep her away from Daz Eden, who he felt wasn't good enough. In late July, Lexi told Jimmy that Carrie and Nick were getting married in Thailand. In December 2008, Lexi tried to contact her after she, Scarlett, Jimmy and Carl were evicted from Home Farm. Scarlett initially wanted to join Carrie in Canada permanently but later changed her mind.
Lexi married Carl on 31 March 2009, and was disappointed Carrie couldn't attend, although she sent her a garter.