Organisers were selling 40 tickets at $45 each and last night there were only four left.
"Going through cancer isn't cheap with all the doctor visits, special food and other costs we don't even think about," one of the event organisers, Melissa Howell, said.
"So it would be nice to gift a little bit of money to the family just before Christmas."
She said when she found out about Katrina, she wanted to do something to help.
"The thing I love about Katrina is she hasn't let this get to her, she's just been positive throughout the whole thing - about the whole cancer journey - and she uses humour to get her through it but at the same time she's very honest and real," Mrs Howell said.
"She's just amazing, she's inspiring."
When Katrina found out about the event and what her friends had organised, she said: "I really have no words that are ever going to say exactly how I feel about what's happening.
"But thank you all so much, it's very, very overwhelming and I can't say thank you enough. I'm blown away at the amount of effort [that has] gone into this, if I didn't know who it was for I would think it was for the Queen. You are all amazing humans."
Katrina also has her partner Luke and her three children Portia, 9, Kayde, 5, and Casey, 2, supporting her.
