But the 57-year-old South Dunedin resident was not what she seemed.
As soon as Pearson discovered the PIN for the woman's eftpos card, she "mercilessly" ripped her off, bleeding the victim's accounts of more than $7000 over 10 months.
When the woman, who suffers from mild dementia, discovered the funds were missing, she ended up at the police station watching footage of someone making a withdrawal from her account.
She recognised the swindler immediately.
"I don't swear but I said, for the first time ever `that's the bitch, Dorothy Pearson, and she lives right across the street from me'," the victim told the Otago Daily Times.
The rare expletive "eased the pain" at the time, the committed churchgoer said.
Pearson appeared in the Dunedin District Court this week after pleading guilty to 10 counts of using a document for a pecuniary advantage.
The defendant, who had been a caregiver for 20 years before losing her job recently, had a clean criminal record and argued she should not be photographed in court because she was not a threat to the community.
Judge Philip Connell, though, said the offending was significant and potential future employers should be forewarned about the woman's ability to commit such fraud.
Pearson began popping over to the 79-year-old's small unit and immediately discovered the woman's weakness.
"I love pussy cats," she said.
So Pearson brought over her cat, they drank tea and by May she was helping the woman with her groceries.
As soon as she found out the PIN for the woman's cash card, the offending began.
Pearson would buy groceries for the neighbour, some for herself - often of a greater value - and withdraw cash, too.
The arrangement ended when the victim found the woman going through her drawers around September.
But the rip-off continued.
"She knew where I kept that card," the victim said.
In the ensuing five months, Pearson withdrew nearly $5500.
First she claimed the money was used for bills but later said it was to pay off a blackmailer, though she would not name them.
Judge Connell was frank: "I don't believe you."
Since Pearson had now lost her job and was waiting for her benefit to start, Judge Connell said he could only impose reparation of $3500.
It will be repaid at $30 a week, meaning it would be more than two years until the debt was satisfied.
"I might be dead by then," the victim said.
Pearson was also sentenced to five months' community detention, with an 8pm-to-7am curfew, at the house across the road from the victim.
So the pair might be seeing more of each other.
"I stand at my kitchen sink, look over there and think `you're going to reap what you sow, girl'."
