She tracked down the teenager who stole her son's bicycle, and told him to "stop stealing because you're terrible at it" and will end up in prison.
This was part of the "life lecture" which Ms Vonnie Sandlan gave to the culprit, whom she managed to trace through social media.
Her son Findlay's bicycle had been stolen in Glasgow city centre just after 9.30pm on Saturday (July 8) night, taken from outside a McDonald's on Argyle Street.
The 16-year-old was "distraught" as he had bought the bicycle with his birthday money just a few days before, said Ms Sandlan in a Facebook Live video on Sunday (July 9).
"He's been less upset when pets have died," she said.
In the video which has since been viewed about 18,000 times and shared over a hundred times, Ms Sandlan also explained how she posed as a buyer of the stolen bicycle, after it was posted for sale on Gumtree.
She had reported the theft to the police, but understood they had other more important things to deal with, so she took matters into her own hands after verifying that it was indeed her son's bicycle.
She and her husband Bob arranged a meet-up with the thief outside The Forge shopping centre, while a friend filmed the encounter from a nearby bus stop.
"The kid came over and he stopped in front of the bike and I was giving it big smiles and went over and put my hand on the bike and I said 'Thanks so much for coming out to meet us on such a miserable day as well, we would have came to your house'," she recounted.
After checking the serial number underneath the bicycle frame, she told the boy "This is my bike" and the boy started crying.
He asked her if the bike was really hers, and she said: "Yeah, it's really my bike. It's not your bike, is it?"
From there, it spun into a "life lecture" on how the moment was a turning point in his life, and he could have been much worse off if someone else other than her had turned up and beat him up to retrieve the bicycle.
Ms Sandlan, former president of the National Union of Students Scotland, told the boy he should be thinking of his future.
"I said, you know what, if school's not working out for you, you need to start thinking about college or like go and do an apprenticeship or something. Stop stealing because you're terrible at it and you're going to end up in Barlinnie."
Barlinnie is Glasgow's prison.
She was then seen laughing and even gave the thief a hug.
While a part of her hoped that the culprit gets in trouble and it scares him into learning a lesson, she added: "Part of me hopes that he just genuinely takes it as an opportunity to make some better life choices."
According to the BBC, a police spokesman said: "Always use 101 in circumstances like this. Let us know what's happening and let us deal with the confrontation side of things."
A Gumtree spokesman told The Straits Times: “We do not tolerate the listing of stolen items on our site, and have measures in place to ensure that our site is a safe place to buy bikes and accessories."
Users are encouraged to report anything suspicious through the "Report" button accompanying every ad on the website, following which a safety team would investigate, said the spokesperson. If users are concerned that the item they are viewing is stolen, they should not buy it, and instead report it to the police.
He added: "We’re pleased to hear that Vonnie and her son Findlay have been reunited with their bike, and recommend that all bike owners register their serial number with a service such as Bike Register.”