Teenager Liz Cooper was with her parents when they spotted the 45-year-old woman threatening to jump into the River Ouse in York.
The woman had climbed over a barrier towards the river when the teenager begged her to stop telling her: "You don't want me or my little sister to see you go over do you?"
Liz told her local paper: "She wouldn't come down for my mum or her friend and I said if she didn't get down I would start crying and she said 'don't do that you remind me of my daughter'.
"I was just acting on instinct to get her away and distract her.
"It just came naturally to try and distract her from whatever she was thinking about that was making her want to jump.
"When we sat down she started talking and seemed fine."
Liz's mum Bev said: "Liz was amazing. The woman was clearly going through such a bad time. Then Liz sat and talked to her about swimming and music and asked about her family.
"It was unbelievable. I think teenagers get such a bad press so it would be great for her to have some recognition.
"She amazed me. Me and her father just stood there and she just took charge and really, really deserves some credit."
North Yorkshire Police were called after the woman had been led to safety by the Cooper family. She was then taken to hospital.
A spokeswoman said: "The public spirited and caring actions of the member of the public who talked the lady down from the bridge are commendable.
"They acted selflessly in what must have been a very distressing situation for everyone involved."
More on Parentdish: