She was initially hoping to raise around $3000, however had raised almost that from entries alone.
The event is being run by MAD Made Events, which specialises in Amazing Race events.
Teams of four to six people will complete in a host of challenges all over the Whangarei Heads area.
The amazing race starts at 1pm from the Parua Bay Community Centre and will be followed by a prizegiving at the end of the day.
Ms Schonewille has lived in the area for the past 22 years, and said the little community "has been awesome".
She said the amazing race is the second big event for her after an indoor netball tournament was held earlier in the year.
"The first I knew about them (events) was when I saw them on Facebook."
Ms Schonewille said there was more than 100 people at the netball and, while there were plenty of people she knew there, she was blown away by how many people she didn't know who took part.
She plans to take part in the event tomorrow, despite receiving treatment during the week.
"I'm going to give it a go, see how I go."
Ms Schonewille said the donations had been a massive support, and were "so appreciated".
She hasn't been able to work since April, and said the donations eased the financial stress.
Ms Schonewille said all the money was being used for Vitamin C or other treatments, which are really expensive.
Another friend has set up a givealittle page for her, which reads "If you know her, you love her". To donate, go to https://givealittle.co.nz/cause/melanieschonewille