"I never thought for one second I'd be standing before you," an emotional Thibault, 76, told Quebec court Judge Carol St-Cyr.
"Since my youth, I've always helped everyone...I can't imagine that my grandchildren will have a memory of their grandmother being treated like a thief."
Prosecutor Marcel Guimont said the ex-Quebec vice-regal should also reimburse a total of $430,000 to the province and the federal government.
The judge will hand down his sentence Sept. 30.
Thibault's legal woes started after a report by the federal and provincial auditors general in 2007 revealed she claimed more than $700,000 in alleged improper expenses during her spell in the vice-regal post between 1997 and 2007.
During her mandate, Thibault claimed expenses for travel, dinner with friends and family, ski and golf outings as well as for a specially adapted golf cart.
She argued the extra spending was due to her being a quadriplegic and needing certain requirements for transportation and security.
Marc Labelle, Thibault's lawyer, argued she had to start claiming expenses to maintain her active schedule as the Queen's representative in Quebec.
Of the amount the Crown wants reimbursed, $92,000 is for Quebec officials and $338,000 is owed to the federal authorities.
Guimont argued there were several aggravating factors in Thibault's case, including the amount of the fraud and the abuse of position.
As the province's most senior civil servant, she held an important role that included swearing in the premier, he said.
"She was supposed to serve as an example for the entire population," Guimont said, noting a community sentence would not be acceptable. "This may cause disillusionment among taxpayers in respect to the basic institutions of democratic life."
Labelle said in his arguments Thursday that a 12-month sentence in the community would suffice.
The veteran defence lawyer told the court the most Thibault should repay is $372,000 — with $272,000 coming from money left in a foundation under her name that helps the disabled.
The money in the foundation coffers are from public donations.
Thibault pleaded guilty last December to one charge of fraud and one of breach of trust.
Fraud carries a maximum sentence of 14 years while the maximum term for the breach of trust is five years.
Even as the criminal case winds to a close, Thibault's legal worries are not over.
Quebec revenue officials say she owes the province $808,000 while the federal Revenue Department is seeking $676,000.
Thibault's partner and longtime aide, Real Cloutier, lashed out at the Crown's recommendation, calling it an abuse of power.
''Madame Thibault is on her knees, her head lowered, she's crying, she's devastated and she can't be any more remorseful than she is,'' said Real Cloutier.
''And people are trying to cut her head off with a sabre...I hope someone somewhere wakes up. If a man had done this, he would have been treated very differently.''