Molly experienced first-hand the affect the house has on families like her own. It inspired her to start a fundraising campaign for the charity after she was declared cancer free in April.

By her 13^th birthday on July 27 - one year after she was diagnosed - Molly raised an incredible $174,219.

Ronald McDonald House Charities head of marketing and fundraising Arani Duggan said Molly's result was incredible.

"I think the reason Molly's story resonated with so many people is because everyone can imagine being in that same situation. It can happen to any of us at any time," Ms Duggan said.

"For this young woman to have gone through what she went through and then have done something so courageous and out her story out there to support other families... I've never seen anything like it."

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When families stay at Ronald McDonald House they don't pay a cent. But every night costs the organisation $160 in running costs, from paying the electricity bills to stocking the pantry and running education programs.

The families are usually referred by a GP, specialist or social worker.

For Molly, her dad John turned up at the door of Ronald McDonald House and asked if a room was free after he heard about it from a nurse at Westmead.

Molly's Mission was the first campaign Ronald McDonald House Charities Greater Western had ever run. The result blew everyone away.

While there was never a doubt she would raise her initial $46,000 goal, Ms Duggan said the overwhelming response took everyone by surprise.

But while the money was amazing, Molly's Mission had another impact.

"I know across social media all the families currently staying in the house were commenting on [Molly's] posts and thanking her. It was more than just the fact she was raising the money and that helps us keep our doors open, it's really about the fact that she helped build a community around our charity and that's incredible," Ms Duggan said.

Community is important at the house. Its motto is 'keeping families close'.

Ms Duggan said most of the families came from regional communities so being able to build a home-away-from-home with other people was really beneficial.

"I don't think anyone can really understand what it's like to have a child that's seriously ill unless you're going through it yourself. They often will make lifelong friends staying in the house," she said.