Denbighshire council said it stood by an enforcement officer's decision to issue the fixed penalty in Ruthin.
The woman, who did not want to be identified, said she had not realised anything had been dropped on the floor.
Residents started a collection after the issue was raised on Facebook. Some claimed she had been treated unfairly.
While the council acknowledged "littering can prove an emotive issue",  a spokesman said the authority had decided to "act on the evidence".
"This lady does have the right to challenge the fixed penalty notice and there is a process to follow which is outlined within the notice itself," he added.
Residents in a Denbighshire town have paid the £75 litter fine picked up by an elderly woman after she claimed to have dropped a receipt by accident.