WASILLA, Alaska — Sherry Johnston is back in her Wasilla home after a judge agreed to let her serve a three-year jail sentence with an ankle monitoring device, according to her attorney.

Johnston is the mother of Levi Johnston, the father of former Gov. Sarah Palin's grandson, Tripp.

She was sentenced last month to three years in jail and three years' probation for dealing the prescription painkiller OxyContin. She had been jailed at Hiland Mountain Correctional Center in Eagle River since August.

Johnston returned to her home off Wasilla-Fishhook Road on Monday, according to her attorney, Rex Butler.

At Hiland, Johnston fielded requests from other inmates for Levi's autograph and "posters of his Playgirl shoot," Butler said. "People were jealous of what her son is doing. Some people said, 'Oh, you shouldn't let him do something like Playgirl.' "

Sherry Johnston is under "intensive monitoring," he said. He said state corrections officers are responsible for enforcing her house arrest, which includes a condition she be near a land line at all times, except for four hours a week when she can leave home.

Corrections department spokesman Richard Schmitz did not immediately return telephone calls seeking comment.

Butler said Johnston suffers from serious medical problems, scurvy and chronic pain from nerve damage stemming from pelvic surgery. The pain requires Johnston to wear implanted medication pumps, he said.

Levi Johnston no longer lives at home, Butler said, but Sherry Johnston's teenage daughter, Mercede, still does.