CHARLIE SHEEN‘s ex-wife, BROOKE MUELLER has volunteered to extend her rehab treatment, and even quit smoking just to show how serious she is about getting her life back together.

Late last year, Brooke was arrested in Aspen, Colorado for cocaine possession, and Charlie Sheen had to bail her out of jail. She promptly checked herself into rehab from out-of-state, perhaps in a bid not to lose custody of her sons. But out of the blue, Brooke says she’s clocking in for a longer stint at the treatment center, and has even quit smoking in an effort at detoxification…

Hmmm…wonder what the huge draw for Brooke at the rehab center is.

“This is a dramatic turn of events for Brooke as this is the first time she has ever voluntarily decided to stay in rehab. This program she is in is working, and Brooke is getting sober for herself, and that is the first time she has ever said that. In the past, family, friends have forced her into rehab, but not this time. Brooke is taking an active role in her sobriety,”

a source revealed to RadarOnline of Brooke‘s decision to extend her stay in rehab beyond the requisite 30 days.

“Brooke quit smoking on her own, she doesn’t want to do anything unhealthy to herself anymore. Her treatment team is so impressed with her accomplishments. Brooke has said instead of smoking cigarette’s, she will take vitamins!”

The source continued. And we’re talking about a 10-year chain-smoker here.

Brooke Mueller is expected to stay in rehab for another month, and somewhere in Hollywood, a newly lucid Charlie Sheen is heaving a great sigh of relief…

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