Stacey Smart, who lives about 40 kilometres from Ms Papini, was reported missing by her daughter, Nichole Santos-Hamann.
Ms Santos-Hamann says she hadn’t spoken to her mother since October 12 and started to become concerned before finally reporting it to police the same day Keith Papini reported his wife’s disappearance, reports The Trinity Journal.
Despite the close proximity, Trinity County Sheriff’s authorities have said there doesn’t appear to be a link between the two cases.
Ms Smart’s family have been working to search the local area and are now reportedly receiving advice from self-described kidnap consultant Cameron Gamble, who also advised the Papini family during the mother-of-two’s disappearance.
“He’s helping us, he’s giving us advice and kind of helping us with coming up with backers, to help us with a bounty or reward leading up to her whereabouts, what could have happened,” Ms Santos-Hamann told local newspaper The Record Searchlight.
“We really don’t know what happened to her. We know it’s not normal. Something is very wrong.”
This latest twist comes just days after news that a girl whom Sherri and her husband Keith Papini went to school with, also went missing on the same road 18 years ago.
Tera Lynn Smith was just 16 when she went missing on August 22, 1998, along the Old Oregan Trail. But unlike Sherri, Tera was never found.
When 34-year-old Papini went missing, local residents immediately drew similarities to the cold case – including the two women’s eerily similar appearance.
“They look similar and the circumstances are very similar. That was the last one people were scared over,” Lianne Bowman, the owner of a dog-grooming business a short drive from where Mrs Papini’s iPhone was recovered, told the Sacramento Bee.
The 16-year-old is believed to have been murdered by her marriedmartial arts instructor Troy Zink, with whom she had been having a relationship at the time. He was the last person to see her alive, reportedly requesting money from him and becoming angry when he refused, reports News Corp.
He claims he then dropped her off at near the Old Oregon Trail before driving alone to “pray” before returning home around 11:30pm.
A lack of evidence meant he was never charged.
Keith Papini reached out to Tera’s father, Terry Smith, in the early days of his wife’s disappearance.
'Keith came to ask our advice and tap in to our experience, find out what we'd do differently, if we were happy with the way law enforcement had handled our case,” Mr Smith told the Daily Mail.
“In many ways it’s worse than what we had to go through because at least we pretty much knew who did it, and what he did, and even though we never found her body, we’ve kind of come to terms with that,” he added to The Sacramento Bee while Ms Papini was still missing.
“In the Papini case, they’ve got nothing. Nothing at all. I didn’t have a lot of comfort to offer him. I’m not real confident that anything’s going to come out of it, but how do you tell somebody five days after their wife’s gone missing that she’s probably gone for good?”
Shasta County Sheriff Tom Bosenko, who also worked on Tera’s case, says the similarities between the cases are undeniable, but it’s unlikely that they are related.
“Sherri is 34 years old, but she looks much younger,” Mr Bosenko said when quizzed by reporters. “They could probably pass for sisters.”
Investigations into Ms Papini's disappearance are still ongoing.