"They took off her big raincoat which covered her whole body and discovered the scarf was wrapped around her neck," she said. "It was a freak accident."
Kenny said another man, who she believed was a surf lifesaver, also stopped to help before the police, firefighters and St John Ambulance arrived.
"Everyone was trying to keep her warm and dry," she said.
Kenny said she and her cousin had blessed the site after ambulance staff laid the woman down on her front lawn.
"It was a terrible sight ... I couldn't not do anything," she said. "It was so sudden and she passed away right here."
Kenny said it looked like the woman - who she guessed was in her mid-60s - was heading to the Papamoa Plaza to do her groceries when the accident happened.
"She had shopping bags over the handlebars," she said.
The skid marks on the footpath outside suggested the woman had tried to stop the mobility scooter, Kenny said. "It looked like she was trying to stop it with force."
The incident had Kenny warning other people about the safety of riding mobility scooters.
She said her mother uses a mobility scooter which had safety guards over the wheels, but this one didn't. "The wheels were more exposed ... it was a late model scooter."
Police have said in a statement that an item of clothing became caught in one of the wheels of the mobility scooter, causing the woman to lose consciousness.
Despite attempts from members of the public to save the woman, she could not be revived.
The woman's death will be referred to the Coroner.