Add his mom's legal fees to Levi Johnston's list of bills to pay.

Sherry Johnston pleaded guilty yesterday in Alaska Superior Court to one count of possession with intent to deliver the prescription painkiller OxyContin.

We might be seeing Levi Johnston nude sooner than we thought!

Sherry, 43, the grandmother of Tripp Johnston, whose mother is Bristol Palin, daughter of former Alaska Governor Sarah Palin, lives in Wasilla, Alaska.

She will be sentenced in November.

A plea deal calls for her to be sentenced to five years in prison, with two years suspended. Her attorney said the deal includes three years probation as well.

"That's pretty," Sherry Johnston said as a court officer placed pink handcuffs - a gift from an Arizona sheriff - around her wrists, for reasons unknown.

Johnston was convicted of a Class A felony, which carries a presumptive sentence of 5-8 years. The plea deal calls for a shorter prison stint because she possessed a small quantity and had no previous drug-related convictions.

Assistant District Attorney Rick Allen said it's not unusual for defendants with mitigating factors like Johnston's to get half the minimum sentence.

Sherry Johnston is jailed at Hiland Mountain Correctional Center while awaiting sentencing and could serve time there, or at home with ankle monitoring.