Carmel is first seen in Walford in June 1986 when she is assigned as Michelle Fowler's health visitor. West Indian by origin, British by education, Carmel is unmistakable with her long dreadlocks and colourful clothing. Carmel is kept extremely busy in Walford as she has all the difficult cases - Mary Smith, a prostitute, whose baby, Annie, has been removed; Sue Osman, a mentally unstable mother who is obsessed with her baby, Ali's, welfare; Donna Ludlow, a self-destructing heroin addict, and jobless Arthur Fowler, among others.
In December 1986, Carmel starts dating Kelvin Carpenter, much to his parents' dismay. Carmel later moves into the ground floor flat at number 3 Albert Square and she and Kelvin live together for a while. However, their age difference takes its toll on Carmel, who grows tired of Kelvin's immature behaviour. She eventually throws Kelvin out after publicly dumping him in The Queen Victoria public house.
Shortly after Carmel moves to the Square, her brother Darren Roberts and his children, Junior and Aisha Roberts, join her. Darren and Carmel are complete opposite of each other; Darren is inconsiderate and often dabbles on the wrong side of the law with dodgy scams, such as porn video laundering and instigating a counterfeit money ring. Carmel despairs over his thoughtless behaviour and criminal antics, but he ignores her and she regularly takes over caring for his two young children. Junior proves to be troublesome, and after Carmel discovers that he has been playing truant from school for some time, she reports Darren to the truancy officer as an irresponsible parent. This does not please Darren and he is even more annoyed when Carmel refuses flatly to put up with his behaviour any longer. Animosity between the two increases when Carmel starts dating Matthew Jackson later that year; Darren is unhappy about his sister dating a white man. Carmel defends Matthew against her brother's racism, and after Darren cons Ian Beale, she throws him out. Darren then leaves alone, leaving his children so Carmel sends them to her parents as she only has a one bedroom flat.
In September 1988, Matthew moves into Carmel's flat and the two are soon engaged. Matthew is well liked in the community, even convincing Carmel's skeptical father that he is genuine and Carmel begins planning their wedding. She wants to invite Matthew's mother, Lynna, but he is opposed to this as Lynna abandoned him at 15 and has had no subsequent contact. Carmel and Matthew marry in January 1989, but the day is ruined when Matthew sees his mother there. Carmel contacted her regardless, thinking Matthew would be pleased, but he is furious. After shunning their reception party, Matthew threatens to leave Carmel and when she tries to stop him, he grabs her by the throat, holds her up against a wall and berates her for her interference. Carmel is petrified and upon seeing her fear, Matthew releases her and begins apologising profusely. Carmel is shaken, but Matthew convinces her that his apology is sincere, so she drops the matter.
More problems arise for the newlyweds when Carmel's sister, Maxine Roberts, announces that their parents can't cope with Junior and Aisha. She states that if Carmel does not take the children, they will be put into care. Matthew is unwilling but after Carmel's father has a stroke, Maxine brings the children to Carmel so they move in with her and Matthew. He resents them as Carmel's time is being diverted from him; finding Junior, in particular, difficult to cope with. They regularly clash, causing further animosity between Matthew and Carmel and Matthew becomes violent again, punching Carmel during an argument about Junior. She has some nasty bruises but once again a tearful Matthew convinces her to forgive him. Matthew's behaviour alternates between contrite and caring to hot-tempered and violent, for seemingly no reason. Nevertheless, Carmel loves him and stays with him as she believes she can help him combat and contain his rage but Junior soon realises why his aunt is constantly bruised and tries to stop the violence by telling people about the abuse but this only makes matters worse. Matthew becomes irrationally jealous of Carmel's friendship with David Samuels, and during a family meal, he turns violent again and attempting to protect Carmel, Junior stabs Matthew with a kitchen knife and he is rushed to hospital, where he tries to convince Carmel that he has changed. She allows him to come home and tries to get him professional help but Matthew refuses, appalled by the idea and begins smashing up the house and threatening Carmel with more violence. Finally realising that she cannot help Matthew, Carmel ends their relationship. She throws Matthew out and he leaves Walford in July 1989. The following month, Carmel's father dies, so she leaves Walford with Junior and Aisha to look after her mother. Her last appearance is in August 1989.