2006-2011: Conception, birth and Viv's death
Since Bob and Viv's remarriage in 2006 they had both wanted a child together. However, plans changed when Bob's daughter Dawn Hope died in a show home explosion in July 2006. On the day of Dawn's funeral, Viv collapses and was found by her daughter Donna Windsor-Dingle. At the hospital, doctors revealed that Viv was pregnant News spread quickly as Donna tells her half-brother and Viv's son Scott Windsor and her husband Marlon Dingle and Scott tells Dawn's ex-husband Terry Woods. Both Scott and Terry told Bob while his ex-wife Jean Hope with Terry and Dawn's son TJ Woods was inside. In August, Viv was ready to have an abortion when Bob, Jean, Scott and Donna stopped her.
On 9th February 2007, Viv went into labour, and gave birth to first a girl and then a boy. Bob helps deliver the baby girl while her younger brother is delivered by village veterinarian Paddy Kirk. Having been born in a shed on the moors, Viv and Bob decide to name the children Cathrine and Heathcliffe, Cathy and Heath for short.
The Twins are baptised in May 2007, with nine godparents; Terry, Donna, Marlon, Paddy, Paddy's ex-wife Emily Kirk, Bob's two children Jamie Hope and Roxy Lockhart, Bob's brother Eddie Hope and Viv's stepdaughter Kelly Windsor. In July 2007, they are entered in a "Cute Kids" competition, which Heath wins.
In 2008, Viv begins raising money for children's charities, however, the man she entrusts with the charity money takes it and vanishes. By a series of mishaps, Viv implicates herself and is charged with conspiracy to defraud. With the help of a private investigator, she finds the man, but he threatens the twins and gets away. On 20th August 2008, Viv pleads guilty in court and is later sentenced to three years imprisonment. Her voice is later heard on a recording she makes of a bedtime story for Bob, Heath and Cathy.
In July 2009, Viv is released but is heartbroken when the twins don't recognise her. Viv soon reveals that she had not been in touch with Bob and the children because she had been appealing against the length of her sentence. In January 2011, Viv and the twins are inside the Post Office when it is set on fire by Nick Henshall. Bob rescues Cathy and Heath and makes it out alive and Terry Woods attempts to rescue Viv. The Post Office explodes and Terry and Viv are killed.
2012-: Living with Brenda Walker
In late 2012, Bob starts dating Brenda Walker who buys a part of the café and later moves in with them. The twins develop a bond to her and the whole family struggles when in March 2013, she's diagnosed with a brain tumour. In March 2015, Cathy and Heath's half-sister Carly arrives in the village. In August the twins stay with Brenda when Bob is sent to prison for fraud. However, he is released the following month when Carly admits the truth about how she was fully involved in the fraud crime.
In December 2017, Brenda is devastated to find out Bob has been cheating on with another woman. However, she decides to put it aside during Christmas for the twins' sake. After Christmas Brenda tells the twins that she and Bob are splitting up but decides to leave out the reason behind it so they won't hate their father. However, they overhear that he cheated on her and refuses to speak to him.
Despite the affair, Bob and Brenda reconcile and Brenda accepts when Bob proposes to her. After the wedding ceremony in May 2018, Brenda leaves Bob realising she won't settle for second best and Bob moves out of their home at Connelton View whilst the twins stay with Brenda. However, Cathy is convinced they'll make up and questions Bob about returning home. Bob explains he isn't as he's done a selfish thing and Brenda deserves better. When Brenda realises Bob is still with Laurel Thomas she informs the twins of her and Bob's relationship. Bob tries to explain himself to his children and says he's sorry. The next day, a furious Cathy insults Laurel.
On 24th May 2018, Heath and Cathy set fire to a pile of Bob's belongings. When Bob confronts Brenda, thinking she was responsible, Cathy admits she and Heath did it. Bob sits them down and reminds his children that he loves them but states if they ever do anything like that again, they'll be in a whole heap of trouble but the twins walk out. Brenda finds them at the playground and Cathy expresses that she believes Bob no longer loves her and Heath. Brenda promises them that he does and assures them it's okay to be angry and upset but states it's never okay to start fires. Bob soon suggests it's better the twins stay at Mulberry Cottage with him and Laurel. Despite Cathy and Heath's refusal to leave Brenda, Bob insists they'll just have to get used to it. In June, Heath and Cathy continue to act up as they adjust to the new living arrangements and miss Brenda.
In November 2018, the twins move back in with Brenda as Bob and Laurel's relationship starts to break down. Approaching Christmas 2018, Bob struggles to get enough money to buy the twins their Christmas presents, disappointing them when he buys the wrong video games. In late January 2019, Bob's financial troubles gets so bad that he has to spend the night outside on a bench. He is found the next day and taken to hospital, suffering from severe hypothermia. He soon gets discharged and moves back in with Brenda and the twins.
In March 2020, Heath and Cathy make a vegan cake in school which Brenda decides to give out to customers in Café Main Street in an attempt to stay on top of trends and not lose customers to Hawksford Outdoor Pursuits. However, she is horrified when the cake gives Dan Spencer an allergic reaction as he's allergic to almonds and the twins reveal they used almond flour. They manage to sort things out but afterwards when Brenda tries the cake she's impressed by how good it is.
Over summer 2021, Cathy gets jealous of all the attention her niece April Windsor is receiving on her memorial page for Donna Windsor. Cathy trolls April on a "dead Donna" social media account and spreads her phone number all while pretending to be on April's side by giving her support. In September 2021, Cathy starts to regret her actions, but its too late as other kids have also started to troll April. Cathy confesses what she has done to April, and after a frosty reception from April, Cathy spends the night in the Cricket Pavilion. The next day Cathy is found by Rhona Goskirk, whom has found out about the bullying, Rhona forces Cathy to confess to Bob and Brenda, which leads to a scuffle between Brenda and Rhona, in which Brenda is pushed to the ground.