The remarkable story of the couple who've fostered over a dozen troubled girls.

John Guthrie and Dennis Cash never wanted children. Somehow, they’ve found themselves fostering and mentoring a dozen children over the last 20 years.

“In our 30s and 40s, life was pretty good for us. We were both reasonably successful, we had a great social life eating out and meeting friends, travelling, just generally enjoying life wherever we could,” Dennis said on Monday night’s Australian Story.

“We’d never really thought about having kids, we were having too good a time as just a couple, then we’d seen an ad in the local newspaper for [foster care not-for-profit Barnardos Australia] and thought ‘well this sounds pretty interesting’.”

For the couple who met through “the original online dating website”, Yvonne Allen & Associates over 30 years ago, the decision to exclusively foster teenage girls came from a concern over how two middle-aged, gay men fostering children might be perceived.

“I had some concerns about fostering young boys, being a same-sex couple, only because of what people might think. So my stipulation was that they had to be girls,” Dennis explained.

Despite their reservations about whether they were really equipped to deal with young children that might have difficulties and need more specialised care, they've since provided a home for girls from the age of 12 until they turned 18 for two decades.

Describing John and Dennis as "quite a team", Sarah, now 30 was the couple's first foster child.

"I was lucky to walk out of my biological family's life alive, I don't think I could have survived any longer with the level of abuse," she said.

Having suffered 21 fractures by the time she arrived at John and Dennis' house at the age of 12, Sarah struggled to adjust to her new environment.

"I made their lives miserable but they loved me. With all my flaws and with all my baggage, they loved me," Sarah said.

"I didn't make their lives easy, but despite this they decided to take on another one."

That 'other one' was Musu, who joined their 'modern family' at 12 after surviving a civil war in Sierra Leone only to be beaten at the hand of a family friend who brought her to Australia as a refugee.

Describing her foster parents as "extraordinary", Musu acknowledged the incredible work John and Dennis continue to do for troubled girls in a similar position to hers.

"I speak from my heart because of my experience and what they've done for myself and other kids, just the amount of love and attention — they're great people and I would give them the world," she said.

Now in their 60s, John and Dennis plan to continue fostering children for as long as there are kids who need them.

"Every day we live vicariously through what they're doing. I love it when we're all together," said John.

"I really can't imagine my life 20 years ago without having these children."

Watch Monday night's full episode of Australian Story, 'Modern Family'. Australian Story airs on Monday nights at 8:30pm on ABC.

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