Last month Rangitonga pleaded guilty to a charge of injuring with intent to injure in the District Court at Tauranga - a charge he had intended defending.
Ms Trainor said she set up the Givealittle page to acknowledge the work of the Association led by Ms Parker.
"It took me years trying through official channels to get some justice, including filing a complaint with the Independent Police Complaint Authority and the Solicitor-General."
"I was told nothing could be done and I thought I was at a dead end until I met Shannon. She was the first person after years of pretty much battling on my own, who told me
something could be done," she said.
Ms Trainor said she knew there were many other victims out there who were faced with similar battles, and through the Givealittle page she wanted to "pay it forward".
"I'm incredibly indebted to Shannon. She is an amazing woman. I know she can help other people also fighting to seek justice but she needs financial support to be able to do that."
Shannon funded the prosecution of Rangitonga herself on my behalf with support from pro-bono lawyers. I hope by setting up this page she can continue to bring justice to other little people like me who obviously need her support and assistance."
Ms Parker said she was humbled by Ms Trainor's support.
"I'm really embarrassed but incredibly grateful to Tasmin who isn't even at the end of her journey, and is already thinking about the next person who needs help and support, and how that can be achieved," she said.
"The point of NZPCA is to ensure that anyone who come to us with police related issues knows their rights, and has a clear understanding of all the options available to them."
The services offered by NZPCA are freely available and fully funded by Ms Parker.
During Ms Trainor's prosecution case she used all her annual leave, took extra days off work, even packed up her two boys on one occasion and called it a "family holiday".
"It's not easy at times but I think it's been good for the kids and helped give compassion towards others and a desire not to ever appear in court themselves," she said.
"I feel huge relief for Tamsin, but we have all fought long and hard to get to this point."
To donate go to /h2> https://givealittle.co.nz/cause/newzealandpoliceconductassociation