Canberra woman Caitlin Horan's journey to the flanks of the storied climb at the heart of Yosemite National Park in the United States began in a Canberra Hospital bed in 2015, and will come full circle on Wednesday.

As she lay in her bed suffering a severe bout of pneumonia, the latest setback after three years fighting Leukemia, to take her mind off her suffering she began following an incredible athletic feat unfolding on the other side of the world.

Tommy Caldwell, literally a rockstar of the climbing world, had begun attempting a new route up the face of the mountain with fellow climber Kevin Jorgeson, on a route now known as the dawn wall, due to it being the first place lit by the morning sun.

So hard was the climb up the slick rock with tiny cracks and holds the size of matchboxes the only thing to grip on to, that most had written it off as unclimbable. The pair had spent close to a decade planning and practicing the 'impossible' route before attempting what became a 19-day epic battle, beamed live across the world.

Inspired by what she was seeing but barely able to move, Ms Horan decided if anything would get her back to health, it would be following in their footsteps. Last week she returned from her first trip to Yosemite, and on Wednesday she will get her chance to thank the pair in person.

Caldwell and Jorgeson are in Canberra as part of a global speaking tour, documenting their incredible journey up the near featureless wall, labelled by many as among the greatest athletic achievements in living memory. The feat was documented in critically acclaimed 2018 film The Dawn Wall.

Ms Horan, who is also involved in charity Climbers Against Cancer, has just returned from her first reconnaissance trip and is planning her own attempt on El Capitan in September, following a more conventional route up the 3000m face known as 'the nose'. She has been granted a special audience with her heroes ahead of their Canberra show.

"These guys have been super inspirational to me in different ways. Tommy's single-minded commitment to doing something previously considered impossible, and Kevin, he was a boulderer without big-wall experience, but he never gave up," Ms Horan said.

It's a long way from the March day in 2012 when she had walked into her GP's office knowing something was wrong but assuming the random bruises, joint pain and fatigue had probably been side effects of training on the rocks of Canberra, Nowra and the Blue Mountains.

"We're going to have to take you to the brink of death and bring you back," her doctor told her as they began administering a nine-out-of-ten dose of chemotherapy, where a ten-out-of-ten would be lethal.

A year later, barely able to stand unaided, she was allowed her first visits outside the hospital. She went straight to the climbing gym in Mitchell.

"I thought about Kevin and said, 'if he can be that brave, maybe I can be that brave one day too'. I'm living on borrowed time now so I might was well start ticking these bucket list things off," Ms Horan said.

It wasn't until several years later when her former teacher and experienced rock climber Peter Blunt wandered into the climbing gym and called her on her long-held dream.

Blunt was putting together a team to attempt the climb, and did she want to be on it?

"I wasn't sure in my mind if I was ready but decided I needed to grab it with both hands and go for it," she said.

The team of three climbers will spend three days attempting the climb later this year, sleeping in portaledges thousands of meters off the ground. Having stood at the base of the mountain and taken in its awe-inspiring scale, she has no disillusions about the challenge ahead.

"It's thrilling just to be on El Cap, even if I never make it to the top it will be one of the most exciting things that will ever happen to me. If I can get there and try really hard I'll be stoked to have the chance," Ms Horan said.

The months ahead will mean hours of meticulous study of the route, training and preparation. But she's also hoping to get something special from Caldwell and Jorgeson tomorrow night.

"I know there will be times when I get scared on El Cap and then I'm going to ask myself, 'what did Tommy tell me?'," Ms Horan said.

Tommy Caldwell and Kevin Jorgeson will appear live on stage at the Canberra Theatre on Wednesday evening. Tickets available through the theatre's website.