Ruth Munro's mother Margaret McPartlin died in September 1993, aged 73.
A sheriff told Munro that being prosecuted for the two-decade long fraud had been punishment enough.
Alloa Sheriff Court was told that the Â£18,577 received by Munro had been repaid in full to the pension companies involved.
The court heard that Mrs McPartlin was the beneficiary of two small widow's pensions.
Between 1993 and May 2015, Munro pretended to administrators of both pension schemes that her mother was still living.
Forms purportedly signed by her mother were returned, and Munro allowed the pensions company to believe Mrs McPartlin was still alive.
Ruairidh Ferguson, prosecuting, said: "The offence came to light when the pensions company itself made a check on the Register of Deaths and discovered that the intended beneficiary had been deceased for a number of years."
Munro, 67, of Tullibody, Clackmannanshire admitted defrauding the pension schemes by inducing them to continue to make payments in the belief that Mrs McPartlin was still alive.
Defence solicitor Harry Couchlin said that it had been "a bizarre and peculiar offence".
He said: "The unusual feature of the situation is that the money wasn't spent, it was retained and it was returned."
Sheriff David Mackie told Munro: "In this case there's little call for retribution.
"You're not somebody who needs to be punished for this and this case is so unusual there's no question of imposing any kind of sentence that would act as a deterrent to anybody else.
"It's enough that you've been put through the process of prosecution."
A grieving daughter received her mother's widow's pensions for 22 years after failing to tell administrators that she had died, a court heard.