Her storylines include relationships with Wayne Ladlow (Malachi Kirby), Dexter Hartman (Khali Best) and Tamwar Masood (Himesh Patel), coping with the aftermath of her mother's rape, having epilepsy and a feud with her older brother Lee Carter (Danny Hatchard).

It was announced that Maddy Hill would be leaving the show, with Nancy departing alongside Tamwar Masood (Himesh Patel) on 22 April 2016.

Wayne is instantly disliked by her father Mick Carter (Danny Dyer) who carries the intended bride over his shoulder to their family-owned pub, The Queen Victoria where Nancy will live.

[3] After punching Dexter Hartman (Khali Best) publicly, Nancy reveals during a family argument that her younger brother Johnny Carter (Sam Strike) is gay.

Dexter follows Nancy when she goes down in to The Queen Vic cellar to change the barrel, she is impressed when he removes his T-shirt and they are interrupted before they start having sex when they hear groaning—Masood Ahmed (Nitin Ganatra) is on the floor of the pub's alleyway after being mugged.

Mick is revealed to have been covering for Ian Beale (Adam Woodyatt), and he publicly humiliates the prostitute involved, Rainie Cross (Tanya Franks), who Nancy gave money to when she was begging earlier in the day.

Nancy is upset when her older brother Lee Carter (Danny Hatchard) attacks Ben Mitchell (Harry Reid), after he makes homophobic comments about Johnny, and fears his volatile behaviour after his service in the army.

During a wedding reception at The Queen Vic, Nancy is taken hostage by Dean in the barrel store, as he tries to burn down the pub as revenge against the Carters.

Learning it would be against his beliefs to run a pub, Nancy suggests they set up a different business, and they trial a curry restaurant night at the laundrette.

Mick and Linda worry about Nancy's health, and refuse to give her more shifts at The Queen Vic, so she applies for a job at another pub, The Rat.

This causes explosive arguments between them, and feeling she has lost her independence, Nancy quits her job at The Queen Vic and begins working and living with Donna Yates (Lisa Hammond).

In March 2017, Mick receives a phonecall from Tamwar revealing that Nancy has been critically injured after being struck by a car while backpacking in Bulgaria.

In April 2021, Nancy returns to Walford to visit Mick and Linda and meets her half-sister Frankie Lewis (Rose Ayling-Ellis).

When Linda continuously interferes with her decision, a frustrated Nancy moves in with Sharon Watts (Letitia Dean) and her half-brother Zack Hudson (James Farrar).

Nancy rekindles her friendship with Zack, and also forgives and supports him when he has the opportunity to participate in a cooking competition, letting him use The Queen Vic's kitchen for practice.

Nancy is devastated to learn that her aunt Tina Carter (Luisa Bradshaw-White) – who is thought to have been on the run – has been murdered by Gray Atkins (Toby-Alexander Smith).

In her absence, Linda's alcoholism continues to worsen, brought on by the guilt of murdering Keanu Taylor (Danny Walters) in self-defence and the threats made against her by his half-sister, Bernadette (Clair Norris).

After being banished from The Queen Vic by Nancy's grandmother Elaine Peacock (Harriet Thorpe), Linda experiences an epiphany where she imagines her death and funeral.

After Nancy slaps Elaine outside the church, she and Lee decide to take a now alcoholic Johnny (now Charlie Suff) along with Ollie and Annie away from Walford.

Hill's casting as Nancy was announced on 29 October 2013, on which the actress said: "I feel incredibly privileged to have been given such an amazing opportunity and I can't wait to start work with such a talented cohort of actors".

"[11] Magazine Epilepsy Today stated "Nancy's seizures are a brave step for the show and are becoming a dramatic fixture in the EastEnders landscape.

She stated that she was excited to be returning, commented that she was looking forward to "reconnecting with all the hilarious, warm, talented cast and crew and meeting some lovely new faces".

Once the episode aired, Hill commented: "It's been great revisiting Nancy and the Square over the past year but it felt like the right time to move on for now.

Hill, alongside Himesh Patel was shortlisted for Best Partnership at the Inside Soap Awards in 2015 for her portrayal of Nancy's relationship with Tamwar,[17] but lost out to Emmerdale's Charlie Hardwick and Chris Chittell (who play Val and Eric Pollard).

[18] The Guardian's Filipa Jodelka praised the introduction of the Carter family, calling Nancy "the true beacon of hope for EastEnders future".

[19] A critic from Huddersfield Daily Examiner said that Dyer and Hill could be the "saviors of EastEnders", stating that Nancy "shoots straight to the top of Characters To Love list when she refuses to serve Dexter in the pub".

[21] Gary Gillatt of Inside Soap praised the pairing of Nancy and Tamwar, saying "At first, Nance and Tam seemed an odd couple even as friends, but truly they are Walford's most sensitive souls.

[23] In the episode broadcast in the UK on 14 February 2014, Nancy wore part of a Gaelic Athletic Association sports kit from St Patrick's College in Ballymena, and it gained some media attention.

Although many fans of the GAA were happy to see this, late campaigner Willie Frazer believed the appearance of the kit belonged to an organisation that "glorifies IRA terrorists", stating he had complained to the BBC.

Heritage opined that Nancy was "leaving far too soon" as since arriving in 2014, she had "been such a force of nature", adding, "She's been funny and sweet and boisterous and—since the biggest subplot of the soap's entire Christmas period was given to her decision to wear a dress to a wedding—it seemed as if EastEnders had much bigger plans for her.