"She is struggling and we are going away on a cruise so we feel better that she will be there while we are gone," said Moira Fiore.
Although Fiore did not name the facility Mueller would be at, she told People that "it is a facility for very wealthy people trying to fight addictions. Brooke is really trying to get her life back."
The past year been rocky for the 33-year-old actress. A month ago, shortly after Charlie Sheen was hospitalized for a drug binge at the Plaza Hotel, he filed for divorce and is fighting for the custody of he and Mueller's 1-and-a-half-year-old boys.
And last February, Mueller checked into The Canyon rehab facility in Malibu, just months after Sheen was arrested and charged for domestic violence when he allegedly put a knife to her throat in a Christmas incident.
Things began looking up when Mueller signed on to do a reality TV show with friend Kathy Hilton and daughter/tabloid princess Paris, according to US magazine.
"Paris and the other girls on the show are going to Las Vegas and Brooke did not feel she could handle it now," Fiore told People. "She was scared. We're all happy she will be in the facility and hope she will be better."