Catherine Pan believes one of the reasons she's alive is because of the flight attendant who helped her mother after she mistakenly stepped off a plane in the wrong city.

"This woman was a huge part of our lives," the 33-year-old Torontonian said.

Catherine wasn't born yet, but the harrowing tale of her mother and brother finding themselves in Toronto, unable to speak English and with nowhere to stay, has become a family legend told at every holiday get together.

"This was a big milestone in my family's life in terms of our immigrant story."

That's why, 35 years later, Catherine and her brother Michael posted a public message to Facebook in hopes of finding the woman they call their "angel."

"This kind of fairy godmother, this angel came down and helped us through a tough situation," Michael Pan, 38, remembers.

'Flashes of that night'

He was four years old in November 1984 when he left China with his mother, Hui Ju. They were travelling to Montreal where his father, Guo Qiang, was waiting for them. There, they would begin their new life in Canada.

But when the plane landed briefly in Toronto, the two walked off with several other travellers thinking they had made it to their final destination.

"I remember flashes of that night — my mom confused in the seat, she was flustered," he said.

Catherine Pan, right, and Michael look at old family photos. They say the story of the 'angel' flight attendant is told at every family get-together. (Yanjun Li/CBC)

Catherine said staff at Air Canada were "really patient" with her mother, miming and using sign language in order to help the lost duo.

"Just with human to human interaction they were able to figure out what exactly had happened," she explains. Her brother points out that there were no cellphones or Google translate apps to assist them.

They eventually got a flight booked for the next day but had nowhere to stay that night. So one of the flight attendants in the room took them back to her place, fed them and gave them a bed for the night.

'It's a very Canadian thing'

"I think it's a very Canadian thing," Catherine said. "It would have been easy for anyone just to go about their day and to leave this situation alone, so that to me is very characteristic of what it means to be Canadian — to go out of your way to help people despite your differences."

The family decided this Christmas they would finally try to find the mystery woman. The Facebook plea has garnered more than 400 shares, and has put them in touch with Air Canada. It was even shared on an Air Canada alumni group, which has pilots who flew for the carrier in the '80s helping in the search.

A photograph shows Michael meeting little sister Catherine for the first time. (Yanjun Li/CBC)

If they find her, the siblings say, they would want to tell her all about their lives now and how lucky they feel to have had the opportunities they've been given.

"Her 12 hours of helping us carried through the next 35 years," Michael said.

He reflects on why the story is resonating with so many people.

"There's a fundamental humanity to the story, that hope that even at the very bottom, there's someone to help lift you back and help you through."