Lorraine Brown, 71, was targeted by a man - who had an accomplice - claiming to be from Yorkshire Water last Tuesday.
Convinced the initial man was legitimate, she let him into her home on Hawthorne Way, Shafton.
Lorraine, who has a physical disability that leaves her struggling to walk for long periods of time, told the Chronicle: “I had a knock on the door from a young man who claimed he was from Yorkshire Water and needed to carry out some routine checks.
“I can’t stand and walk very well and this conversation at the door went on for a while.
“I think he picked up on this as he then insisted that we go inside to sit down and talk further.
“As I was so worried about walking, I rushed to my chair where the man followed behind me, leaving the door open.
“Strangely, I had no red flags until he started asking about my family. I thought these questions weren’t relevant and it started to worry me.
“The door was left unlocked, which leads me to believe the man was trying to distract me while a second person came in and stole a drawer of jewellery.
“Once the man had left and I found out what was stolen I burst into tears. I was devastated.”
Some of the items taken included five designer watches, a gold wedding ring and an amethyst pendant.
“For me it was the emotional loss - those pieces have real sentimental value to me,” Lorraine added.
“They’re not modern pieces, they’ve been passed down through my family and mean an awful lot to me.
“I’m heartbroken and I hope those involved are brought to justice so this doesn’t happen to anyone else in a vulnerable situation.”
Police have warned pensioners to stay alert after fraud experts revealed there has been a rise in related cases throughout the coronavirus crisis.
Local officers are now working alongside the National Crime Agency (NCA), Action Fraud and Age UK as it’s feared the majority of people targeted fell into the elderly bracket, many of whom are in self-isolation due to the virus’ spread.
A spokesperson from South Yorkshire Police said: “Police were called at around 3.50pm on July 28 to reports of a burglary at an address in the Shafton area.
“It is reported that a man entered the address of the victim, a 71-year-old woman, under the false pretences of visiting from Yorkshire Water.
“The victim discovered that a quantity of jewellery had been stolen.
“The man is described as being approximately 20 years old, five foot and seven inches tall with dark brown hair and a medium build.
“He’s believed to have been wearing jeans and trainers and spoke with an Irish accent.
“If you have any information that might help our officers, please call 101 quoting incident number 572 of July 28.”
Mel Tattersfield, from Yorkshire Water, added: “We know that unscrupulous people do attempt to gain access to people’s homes by claiming to be from Yorkshire Water or ‘the water board’.
“We are currently carrying out work in the Shafton area, so it’s important residents remain vigilant at this time to prevent opportunist thieves.
“All our staff wear a uniform and carry photo identity cards which they’re happy to show.
“If a caller claims to be from Yorkshire Water, put the chain on the door before opening it and ask to see their identity card and why they’re visiting.
“If you’re at all unsure and wish to double check the caller’s identity call us before letting them in.”