BANGOR — A Winslow woman was sentenced Tuesday for embezzling more than $800,000 over 20 years from the Waterville lawyer for whom she worked.

Sarah Nale, 39, was sentenced to nine months in prison, nine months of house arrest and two years of supervised release for the scheme, in which she systematically siphoned the money while working as a secretary for Sidney H. Geller. Nale has also been ordered to pay $816,584.74 in restitution.

Nale, who was Geller’s bookkeeper and sole employee, diverted cash and checks from Geller’s law practice. She also wrote herself checks from rents collected from Geller’s Waterville properties on Silver Street, Main Street and College Avenue.

While officials have not been able to prove where all the money went, parts of it were spent on payments for new cars, home improvements and for Nale’s son to play youth hockey, federal prosecutors said Tuesday.

“She wasn’t keeping the books, she was stealing,” prosecutor Chris Ruge said.

Of the roughly $816,000 that Nale stole, $687,000 was from his real estate trust, $21,500 from Geller himself and about $129,000 from his son, David A. Geller.

Sidney Geller spoke during Tuesday’s sentencing hearing, saying he treated Nale “like a daughter” in the two decades they worked together. He said he still lies awake at night and thinks about how it all happened.

“Initially, Sarah admitted to me that she stole $100,000 from David,” Sidney Geller said. “My heart was broken when I learned the amount she stole from me.”

Federal prosecutors reached an agreement with Nale to plead guilty in August.

U.S. District Judge Stacey Neumann delivered the sentence Tuesday, saying Nale had abused a position of trust in a decadeslong scheme to financially exploit the Gellers.

“Mr. Geller trusted you, and he had reason to trust you,” Neumann said. “It’s a serious crime, and it’s going to require a serious punishment.”

Nale said at the sentencing hearing that she stole the money only to provide for her son. She then offered “heartfelt apologies” to the Gellers.

“My actions were not driven by greed,” Nale said, “but by a desire to care for my son.”

Defense lawyer David Bate said Nale comes “from a wholesome background,” and argued that her stealing from the Gellers was a response to post-traumatic stress disorder from several abusive relationships that Nale had left years ago. Bate produced a doctor’s note clarifying that Nale had been diagnosed with PTSD, and “poor judgement” is one of its symptoms.

“She saw it (the money) as solace for her son,” Bate told the court. “It’s not an excuse. It’s a reason.”

Nale’s family had already paid $100,000 in restitution before Tuesday’s sentencing hearing. About a dozen of Nale’s family members attended and spoke during the sentencing, including one of her uncles, Mark Nale, a lawyer at the Elder Law Offices of John and Mark Nale.

Mark Nale said in testimony during sentencing that he plans to give Sarah Nale a job as a bookkeeper at his law firm when she finishes serving her prison sentence.

“What happened here is entirely out of character for our Sarah,” he said. “We believe in her and know she has the strength to move forward.”

Sarah Nale could have been sentenced to a maximum of 33 months in prison and ordered to pay $1 million in restitution, though Neumann said she considered the Nale family’s plans to provide Sarah a safety net and employment in her sentencing.

“We would all do anything for our children. We would jump in front of a bus, if we knew it would save them,” Neumann said. “But by stealing, you make everything you did for your son backfire.”