Hilary Potts was Laurel Thomas's mother and Doug Potts ex-wife. Whilst Laurel was growing up Hilary favoured her other daughter Caroline over Laurel, which caused problems in Hilary and Laurel's relationship as well as Laurel and Caroline's relationship too.
Hilary and Doug visited Laurel and her husband Ashley in April 2007. After they left Laurel and Ashley's house, Hilary and Doug were involved in a car crash, but they both made a full recovery and returned to the village to visit their new grandson Daniel. Whilst Doug and Hilary were eating a meal with Laurel and Ashley, Daniel started to cry but Hilary insisted that Laurel left Daniel to cry it out. Later when Laurel went to check on Daniel he was not breathing she rushed him down the stairs but he was later pronounced dead. Laurel blamed Hilary for Daniel's death and asked her to leave. Hilary and Doug returned a few weeks later and Hilary and Laurel reconciled. Daniel's post mortem revealed that he was a carrier of a cystic fibrosis gene, which puzzled the family as no close relative had the condition.
A few weeks later Hilary discovered that neighbour Melanie Doland's sister had died of cystic fibrosis. This led Hilary to believe that Daniel was not her grandson and the Melanie's son Arthur was, as they were born on the same day, in the same hospital. Her suspicious were heightened when Melanie's husband Greg said that Arthur was allergic to sea food, which ran in Hilary's family. Doug, Laurel and Ashley believed that saying that the babies were mixed up was Hilary's way of dealing with grief, but she phoned the doctor and asked him to double-check Daniel's blood results. Hilary's suspicions were confirmed when the results came back that Daniel and Laurel's blood groups were not compatible and Laurel and Ashley could not be Daniel's biological parents. Laurel was furious with Hilary and slapped her for adding to their grief. When Hilary learned the Dolands were going on holiday to Spain, she offered to look after baby Arthur whilst Melanie packed. Hilary stayed out with Arthur too long and Greg and Melanie missed their flight. Ashley and Laurel were forced to explain the blood results and that there was a strong possibility that Arthur was the Thomas's biological son, as Arthur was the only other baby boy born on the same day as Daniel. Greg and Melanie tried to emigrate to Spain due to their fear of losing Arthur but Ashley stops them. Hilary called the police but they were powerless, this caused Melanie to run away with Arthur. Hilary left after telling Laurel she could not watch her ignore her own flesh and blood. Doug stayed with Laurel and Ashley who were awarded custody of baby Arthur in June 2008. On Arthur's first birthday in August 2008, Hilary phoned Doug and asked for a divorce but they reconciled in January 2011 and went on a cruise together.
Hilary didn't attend Laurel's wedding to Marlon Dingle in September 2014. Doug told Laurel that Hilary had a bug but a few days later, Hilary had all of Doug's belongings sent to Laurel's house. Doug was forced to admit that he and Hilary had split up and she had a new boyfriend named Alberto. A few weeks later Hilary phoned Laurel and told her she and Alberto were getting engaged.
In July 2015, Laurel received a call from Doug telling her that Hilary had passed away from heart problems. She spent the last year of her life very happy with Alberto, and Laurel and Doug learned she had also spent most of her money on Alberto, leaving Laurel with nothing but some pig ornaments.
"So, Ashley, you're a vicar?" (first line)