A 58-year-old woman who continued to collect her father’s state of Hawaii disability payments 21 years after he died was sentenced Thursday to 21 months in federal prison.

U.S. District Judge Helen Gillmor also ordered Lynsie Katherine Williams to perform 300 hours of community service and repay the state $398,887.

Williams has until March 27 to turn herself in to begin serving her sentence. She asked for a later date because she said she may be called as a witness in the California trial of her husband’s alleged murderer. Gillmor denied the request. Details about the murder case were not available.

The U.S. Marshals Service paid for Williams’ transportation from her home in California to attend Thursday’s sentencing hearing. She said her son paid for her return ticket.

Williams pleaded guilty to mail fraud in September. As part of her plea deal, the government promised to drop two money-laundering charges against her.

Her father, Edwin David Callison, was injured on the job at the Kauai Humane Society in 1976, an incident for which he qualified for permanent total disability from the state until his death in January 1990, according to a federal indictment. Callison had directed the state to send his disability checks to his bank in California.

Williams performed care-giving duties for her father in the final years of his life and eventually placed Callison in an assisted-living environment, the indictment said.

The state continued to send disability checks to Collison’s bank because Williams failed to inform the state Department of Labor and Industrial Relation’s Disability Compensation of her father’s death, according to the indictment.

In 1992 Williams opened a joint savings account with Callison by forging her dead father’s signature. She also opened a personal checking account in just her name into which she transferred money from the savings account, the indictment said. She then spent the money she had transferred for her own use.

Williams also forged her father’s signature on forms she mailed to the state in 1998, 2000 and 2011 that indicated that Callison was still alive and eligible for continued disability payments, the indictment said.