BOSTON — She stood before a federal judge yesterday with the plain, unassuming look of a middle-aged woman who worked a 9-to-5 job, raised a family, and wouldn’t dare break the law.

The image of middle-class life.

But according to the U.S. Attorney’s office, Angela Buckborough Platt, a former Cumberland resident, lived a double life — her plain-Jane exterior the cover for an extravagant lifestyle of million-dollar houses and lavish spending sprees, all paid for by stealing $6.9 million from her employer, a Rehoboth construction, landscaping and real-estate holding corporation.

It is the largest private embezzlement in Massachusetts history, according to Assistant U.S. Attorney Jonathan Mitchell.

Platt, 43, was sentenced in U.S. District Court yesterday to four years in federal prison on one count of interstate transportation of stolen property.

Judge William Young gave Platt three years supervised release after her prison sentence and ordered her to pay her former employer, J&J Materials, $4.4 million in restitution (Platt has been paid back $2.5 million by surrendering much of her assets).

Platt will begin serving her sentence July 19. Until then, she is spending her final days of freedom with her husband and two children in Pennsylvania, where they now live.

“She is eager to get home for her son’s high school graduation. She understands the significance of the sentence ahead of her,” said Platt’s attorney, R. Bradford Bailey, of the Boston firm Denner Pellegrino.

Platt, a former accountant, was arrested and charged by the U.S. Attorney’s office on Jan. 22 for writing company checks to herself and depositing them into her Rhode Island bank accounts over the course of six years. She pleaded guilty Feb. 12.

Mitchell characterized Platt’s crimes this way: “It was a complete abuse of trust, done face to face, everyday, in a very calculating way.”

The tale of what Platt did with her ill-gotten millions is hard to top.

Platt allowed her family to indulge in their every fantasy and lavished gifts on friends and strangers alike.

She purchased a 100-acre estate in a small Vermont town where she and her husband became something of local celebrities, oftentimes picking up the tab for entire restaurants, according to the U.S. Attorney’s office.

She bought a Colonial-era house in Foster and bought her young daughter 10 horses, which they stabled at a farm in Lincoln.

The family had a fleet of 28 automobiles, from classics to custom-built roadsters, and owned a warehouse worth of Hollywood-grade cinematic props, such as a 20-foot tall smoke-emitting dragon and the “talking trees” from the Wizard of Oz.

But the high life went bust when J&J Materials hired another accountant to work with Platt who caught on to her scheme.

At the time, Platt was planning her brother’s wedding, an all-out affair where pianist-composer Burt Bacharach and the New York-based Irish step-dance troupe Riverdance were to perform.

Platt’s lawyer, Bailey, argued in court for leniency, saying that Platt was “driven by an impulse to please others” because she suffered from “narcissistic personality disorder” and anxiety.

Platt’s mother was mentally ill throughout her childhood, he said, which strained the family life and led Platt to abuse alcohol as a teen. Bailey offered up her mother’s death, in 1999, as the “triggering event” for the otherwise “law-abiding” Platt.

In the year that followed, he said, Platt would return to abusing alcohol and begin stealing from her employer.

Judge Young, addressing Platt, said: “You are not suffering from a mental illness. You lied to people that trusted you, over and over again. You spent money because you felt power and happiness helping the people close to you. But most people do that with their own money.”

John P. Ferreira, owner of J&J Materials, said after the proceedings that he was pleased with the sentence and glad that it was finally put to rest.

He had spent many “sleepless nights” searching for reasons why his company’s “bottom-line profits kept sinking” while Platt worked for him, said Ferreira. He had laid off 35 of 140 employees and closed a number of the company’s offices as a result of Platt’s theft.

“It was the worst two years of my life,” Ferreira said. “I felt like a failure, like I could not run the business like I used to.”

Platt sobbed in court as she read from a brief statement, in which she apologized for her actions and the harm she brought to her family, stammering, as she said, “I am very ashamed.”

pmarcelo@projo.com