Kelly (not her real name) said Harding targeted her 73-year-old mum when she was recently widowed and in a vulnerable state.
"He is very clever with who he targets. Will usually has three ladies on the go at one time and abuses them in different ways."
Kelly's mother got engaged to Harding and he moved into the family home in 2015.
"He became a big part of our lives. My teenage children saw him as a granddad figure, he has had a massive impact on our lives."
Kelly said Harding had purchased a house and the day the deposit was due he left.
"He told us he was going to the dairy and never returned."
She claimed, despite her mother having no money to buy another house, she was talked into co-signing the contract with Harding.
Kelly said when Harding vanished her mother had to pay almost $8000 to the vendors and in lawyers' fees.
"It's absolutely devastating. I think it's like a grieving process because we really did love the guy."
She described Harding as the best con-artist she had ever seen.
"More and more victims are coming forward but they don't want to speak to the police. People feel sorry for him because he's old but he has been a con-artist his whole life and he is very good at what he does.
"I don't think he would have got caught if it was just one victim but the fact there has been three of us, has made all the difference," Kelly said.
Being Elderly Abuse Awareness Week, which runs from June 15 to June 22, Kelly said it was important for young people to watch out for people like Harding.
"There are lots of these people in the community like Will and it's important for victims to come forward and not to feel ashamed," Kelly said.
Harding was arrested in Levin on May 17 after being on the run for almost a year and had previously entered a not guilty plea to all charges.
He was convicted of one charge for loss by deception over $1000, two charges obtaining by deception over $1000 and one charge for failing to answer the district court bail.
Judge Anthony Couch convicted and remanded Harding in custody until sentencing on August 7.
Timeline
March: Several formal complaints laid against Harding
April: Harding believed to have left Whanganui
May 14: Police launch public appeal for sightings of Harding
May 20: Harding turns himself into police in Hawke's Bay
May 24: Doesn't make his court appearance citing health concerns
June 28: Harding enters not guilty pleas at the Whanganui District Court and is remanded on bail
Late July/early August: Leaves his bail address in Liverpool St, Whanganui
August 9: Fails to reappear in the Whanganui District Court. A visit to his home reveals he was no longer at the bail address
Late August: Banking activities indicate Harding could be in Wellington
September 6: Police launch another public appeal for sightings of Harding
September 8: Alert for Harding put on Police Ten 7
December: Stays with a Wellington couple, claiming he'd lost his house in the November 7.8 quake
May: An anonymous tip-off leads police to Harding at a Levin address, appears in court and is this time remanded in custody
June 15: Appears in the Whanganui District Court and pleads guilty to all four charges.
