Nell Rebecchi, played by Scarlett Anderson, made her first screen appearance during the episode broadcast on 7 January 2013. She is the daughter of Sonya (Eve Morey) and Toadfish Rebecchi (Ryan Moloney). Anderson was just four weeks old when she made her debut as Nell. Morey revealed that she instantly fell in love with her and joked that she had trouble letting her go after filming. She said "I just want her there all the time! I come home all excited about how I've been able to work with the baby. She's called Scarlett in real life and she's such a beautiful baby. Having her around just lifts everyone's mood, so we're very lucky."
Morey believed that she "wore down the writers" to give Sonya and Toadie a baby. She commented "After everything they have been through, it just seems like the most natural thing for these characters." Morey's character was pregnant at the same time as Vanessa Villante (Alin Sumarwata), which allowed the two women to share their experiences. Both actresses were required to wear prosthetic bumps, which would be increased in size every few weeks. Morey stated that she became attached to hers and would constantly rub it. On-screen, Sonya opts to give birth at home, but experiences serious complications and has to undergo a caesarean section at the hospital. Toadie and Callum Jones (Morgan Baker) are left "to frantically wait for news" and when Karl Kennedy (Alan Fletcher) cannot confirm the health of the baby, Toadie assumes that his daughter has died. A Soap World reporter said "Toadie is in agony until Karl finally reports that little Nell is healthy and happy. The new father joins a recovering Sonya and Callum to celebrate the newest addition to the family".
When Sonya and Toadie decide to have a baby, they initially struggle to conceive and Toadie learns he has a low sperm count. The couple think about putting their plans on hold. When Sonya goes to the hospital to give blood, Rhys Lawson (Ben Barber) asks her to take a pregnancy test. Believing the test is negative, Sonya throws it away, but Rhys retrieves it and reveals that the test is positive. Following the first ultrasound scan, Sonya and Toadie argue about whose surname the baby will take and ultimately choose Rebecchi. After learning that they are having a girl, Sonya finds a photo of Nell Mangel and decides to give the name to her daughter. Sonya chooses to have a home birth and goes into labour two weeks early. When a complication arises, she is taken to the hospital and gives birth to Nell via caesarean section. Nell stays in the hospital for a couple of days with Sonya, before she goes home with her family. Sonya and Toadie later throw Nell a naming day ceremony, where she gets to meet her grandmother Angie (Lesley Baker). During his campaign to intimidate Sonya, Robbo Slade (Aaron Jakubenko) moves Nell's pram when she is looking away. Sheila Canning (Colette Mann) brings Nell back to Sonya, explaining that her pram was around the corner.
When Toadie and Sonya realise that Nell has become too reliant on technology to keep her entertained, they go through a 24-hour digital detox. A few weeks later, Nell suffers a fall at the local park when Sonya is briefly distracted. A DHS worker investigates the incident when a formal complaint is made against Sonya. The following year, Nell is stung by a bee and rushed to hospital, as she suffers a mild reaction to the sting. Georgia Brooks (Saskia Hampele) becomes distracted and almost gives Nell an overdose of paracetamol, but Sonya stops her in time. Nell begins biting people and Sonya and Toadie struggle to work out the cause of the issue. While babysitting Nell, Amber Turner (Jenna Rosenow) discovers that she is being influenced by a phone app. When Toadie is left paralysed after an accident, Nell becomes afraid of his wheelchair. Amy Williams (Zoe Cramond) helps out by dressing Toadie up as a spaceman and his wheelchair as a rocket to turn it into a game, which relaxes Nell. Sonya leaves Nell with Toadie, while she goes shopping, but he is unable to chase after Nell when she runs out the front door and into the driveway. Tyler Brennan (Travis Burns) stops Sonya from hitting Nell with her car.