Her father Sholto lost his battle against brain cancer.

The swimmer had just turned 19 when her dad passed last August.

Now, not a morning goes by without McKeown reflecting on her dad, a source of inspiration and perspective: the Olympics is just a swimming race.

"I use it every day that I wake up," McKeown said after breaking the 100 metre backstroke world record last month.

"I know it's a privilege to be on this earth and walk and talk."

Having gone through that, her coach Chris Mooney reckons McKeown can get through anything.

"I didn't expect anyone to have the answers," Mooney said.

"We just trust each other. Just trust in the fact that it was OK to be happy, it was OK to be sad, and it was OK to be vulnerable.

"It was a really good team effort getting from that situation to where we are today.

"I reflect from time to time and I'm pretty proud and pretty impressed with her resilience.

"Her ability to deal with that and be as brave and as tenacious as what she has been with everything going on."

Mooney said there's two sides to McKeown.

"Very humble ... very generous," he said.

"They're probably two values that take a little of bit of time to discover in people but they are very obvious in her.

"She never takes anything for granted, especially of late ... every opportunity she has been given and is given, she is very grateful for.

"I put that down as being a very humble person."

Then, there's McKeown the athlete.

Only six Australian swimmers have won three gold medals at a single Olympics.

McKeown has the chance to join them - in backstroke's 100m and 200m and the 200m individual medley.

"We can't call it that white line fever," Mooney said.

"But when that whistle goes and she gets up on the blocks, she has that ability to morph into that person that is hungry, who has identified all the other sacrifices that other people have made - not just herself.

"Just has this ability to switch it on when it counts."

Mooney helped flicked the switch in mid-June, at Australia's Olympic selection trials on a cold Adelaide night.

Prowling pool deck, he watched McKeown's warm-up intently.

Then, with a nod: "I believe in you," he told her.

The swimmer took Mooney's message as: It's on. You can set a world record.

She did, bettering the previous benchmark of her main rival in Tokyo, American Regan Smith.

"It's absolutely stacked with talent, whether it's the 100 back or 200 back or 200 IM," Mooney said of McKeown's events.

"It's going to require something special, isn't it?"

He's reluctant to say much more.

But he did say.

"We have left no stone unturned here mate," he said.

"When I talk about she is testing well and she's training well, there could be in a little bit something in those sort of statements."

Australian Associated Press