Mueller, the ex-wife of Charlie Sheen, had her original one-year sentence terminated about four months ahead of schedule, reported E! online.
"I spoke to Brooke and she is extremely glad to be able to put this behind her and focus on her kids, her sobriety and her jewelry line," Mueller's rep, Steve Honig, said.
Stemming from her Aspen drug bust in December 2011, Mueller had been placed on probation last May as part of a plea deal that allowed her to avoid jail time following an intensive rehab program.
She was charged with felony drug possession, intent to distribute and misdemeanor assault after she allegedly roughed up a woman at an Aspen nightclub and officers reportedly found between four and five grams' worth of cocaine on her.