When she was a thirteen, with David Wicks, he wanted to hitchhike one summer, into Europe. Staying in hostels, or sleeping on the beach. But when Carol fell pregnant they could no longer do it.
Her family tried to force her to have an abortion but she refused to have the abortion and disagreed. However, Carol's brother Derek Branning hated David and after learning about Carol's pregnancy, Derek beat David up severely and terrorised his family. This resulted in David and his family leaving Walford for Romford in 1976. Carol gave birth to a daughter, Bianca Jackson, in July 1977. By then Carol had lost contact with David. She had numerous relationships with men and had 3 more children, Robbie Jackson, in 1978 by a man named Gary Bolton, Sonia Jackson in 1985 by a man called Terry Cant, and Billie Jackson in 1988 with Alan Jackson, whom she settled down with and married.
Carol's is a feisty, loud and strong character, who is fiercely protective of her children. She arrived in Albert Square in 1993, as a worker in the launderette. She soon moves to Albert Square with her partner Alan, and her four children: Bianca, Robbie, Sonia and Bille. In January 1994, Carol is shocked to see that David has moved back to Walford, and is also living in Albert Square with his mother Pat Butcher, stepfather Frank Butcher and stepsiblings Ricky and Janine Butcher. Carol has to come to terms with her ex living near to her. When it looks like Bianca is about to start a relationship with David, Carol has to reveal to David that Bianca is actually his daughter, who David thought Carol had aborted. Carol starts a rivalry with Pat over this. In February 1995, Bianca is told by David that he is her father.
Carol and Alan get married after Carol's sister April is jilted at the altar. This is despite Carol's father Jim and brother Derek disapproving of the marriage, because Alan is black. However, Alan soon becomes jealous of Carol's friendship with David, and starts an affair, which provokes Carol into having an affair with David. These affairs are short lived, and Carol and Alan soon reunite.
After Billie witnesses an armed robbery, the Jackson family (without Bianca) are moved away from Walford on the Witness Protection Programme. During this time, Carol separates from Alan, and starts a relationship with Dan Sullivan. When the Jacksons return to Walford, Bianca realises that she had a relationship with Dan when she was fifteen. She keeps this from Carol, but they soon begin an affair. When Carol finds out about the affair, she kicks Dan out, tells Ricky Butcher (Bianca's husband), and disowns Bianca. She then moves to Balham with Billie.
Carol comes uninvited to Ricky and Bianca's second wedding, to try and stop her son Billie from attending. Despite initially feuding, Carol and Bianca make up, and Carol moves to Walford. Billie and Carol fight regularly over Carol's controlling parenting, and Billie's gang connections. When Jack Branning gets accidentally shot by one of Billie's gang members, who wanted to shoot Billie, Billie blames himself, and joins the army.
Billie is allowed to come home on his birthday, and Carol organises a party for him and his friends. During the party, Billie drinks too much alcohol, and the next day, he is found dead on the sofa. Carol is distraught, and blames her family, until her brother, Max, tells her Billie only joined the army to get away from her. She bans her family from attending Billie's funeral, so only her, Alan, and Alan's mother Blossom attend. In her grief, Carol tries to kiss Alan, but he rejects her as he has married again, and has a son. Carol plans to commit suicide by overdose, but is interrupted by one of Billie's ex gang members, Connor Stanley. Connor and Carol comfort each other, and end up having sex. Carol however, disapproves of Connor's criminal background, and they break up and get back together many times. During one of the breaks, Connor starts dating Carol's step-granddaughter, Whitney Dean. Connor sleeps with Whitney and Carol at the same time, until Bianca finds out and hits him with a metal pole, causing her to go to prison.
In 2011, Carol started a relationship with Eddie Moon, until she finds out he is seeing Vanessa Gold. In 2012, when David returns to Walford to visit his dying mother Pat, old feelings start to resurface. Carol's brother Derek however hates David because of an old rivalry, and him getting an underage Carol pregnant, so he forbids the reunion. During an argument with Carol, Derek slaps her, which frightens her. The feud between David and Derek eventually escalates to violence. David persuades Carol to leave Walford with him, but after seeing how much she is needed by her grandchildren, he decides to leave without her.
When Bianca is sent back to prison in Suffolk for theft and assault, Carol, along with her grandchildren move away from Walford in order to be closer to her. Carol and her family return to Walford a few months later. On Christmas Day 2012, Derek dies of a heart attack, which upsets and relieves the Branning family. On the day of Derek's funeral, Carol clashes with Max's secret wife Kirsty, telling her that Max doesn't want her in his life.
In late 2013, Carol begins a relationship with Masood Ahmed, but when they arrange a quiet night in at Carol's house, David returns with a whole lot of trouble. He has been having an affair with his boss's wife Naomi, and he has money which his boss, Don, wants. Don orders his henchmen to beat David up, which is severe. The next few weeks, Carol is torn between David and Masood, and doesn't know who she loves. She eventually opts for David, and leaves Masood to go on a meltdown.
In January 2014, Carol finds a lump on her breast and fears she may have breast cancer. She has the lump checked out and a few weeks later, Carol is diagnosed with an aggressive form of breast cancer. This devastates Carol, and only tells David, Bianca and Sonia. In July 2014, She joins Tina to secretly sell weed. Carol stops doing it and reveals that Tina was the one keeping drugs in the cafe when Tiffany takes them. When Charlie leaves his phone at the Butchers, Carol hears Nick Cotton's voice in a message and confronts him. After months of debating, Carol decides to have a double mastectomy and after the operation, Charlie comes to explain what she heard on his phone.