Brooke Mueller, Charlie Sheen‘s ex-wife is back in rehab, and risking being sent to jail after a four-day binge with Sheen.

Mueller is on probation after her arrest in Aspen in December on drug charges has relapsed and Celebuzz has learned that she has checked into a clinic for an addiction to crack cocaine.

Mueller’s rep, Steve Honig confirmed the news today. He said that she voluntarily checked herself into a rehab facility a few weeks ago as planned. According to a source close to Mueller, she met up with Charlie again and partied for four days at his Mulholland Estate home where she eventually fell off the wagon.

As a result, she even missed Mother’s Day with her three-year-old twins with Charlie, Bob and Max. The boys were with Mueller’s mother at the time of her relapse.

Her return to rehab comes less than two months after she was released from another rehab clinic after undergoing treatment for 90 days.

The source added that her family is hoping that she finally understands the consequences of her actions and that she risks losing her kids if she doesn’t get clean. To add to those concerns, a condition of her parole was that she was prohibited from drinking alcohol and had to undergo random urinalysis. If she is found to have violated any of those terms, she would be jailed.