Ms Burton will do the 42.9 kilometres run wearing a T-shirt decorated with their names, and the names of others who have fought cancer.

The run is sure to be an emotional one for Ms Burton.

The 28-year-old from Crace had told her aunt Joy Hennock, who recently died, of her plan to enter the marathon.

Ms Burton has raised more than $3000 for the ACT Cancer Council, and she is asking donors to provide names of people they know who have suffered from cancer for her T-shirt.

''Each person who makes a donation on my fund-raising page, no matter how large or small, is invited to give me names of people either living or passed,'' she said.

''Ideally, I would love to receive so many donations I will have to write names on other items of clothing too.''

Even strangers have approached Ms Burton to share their stories about being affected by cancer.

She said messages of support left by donors were keeping her motivated.

On practice days, Ms Burton rises at 5am and runs as many as 15 kilometres. She ''goes through countless socks and workout gear'' and has visited a physiotherapist several times due to injury.

But the pain is nothing, she says, compared to that of cancer sufferers.

''Every painful step, blister, sore and pulled muscle will seem insignificant in comparison to the pain that cancer causes the patient and their family and friends,'' she said.

''It's wonderful to know that what I'm doing is creating such a positive feeling around a horrible disease.''

That positive feeling has been shared with children, as Ms Burton face paints at fetes to raise funds. She originally aimed to raise $1000 for the Cancer Council. Now having raised more than three times that, she is the highest fund-raiser for the marathon - no mean feat when more than 1500 runners have signed up so far.

■ The Canberra Marathon takes place on April 14. Participants choose to raise funds for one of more than 170 charities. Entries are still open.

You can support Ms Burton here.