"She is struggling with her sobriety and we are going away on a cruise so we feel better that she will be there while we are gone," Mueller's mother, Moira Fiore, told the magazine, adding she is expected to remain in the facility about two weeks.
Though Fiore would not reveal the center's name, she says, "It is a facility for very wealthy people trying to fight addictions. Brooke is really trying to get her life back."
Sheen filed for divorce from Mueller, 33, last month, stating the couple separated last Christmas, when the 45-year-old Two and a Half Menstar was arrested on assault charges.
Sheen and Mueller, his third wife, were married in May 2008. They have twin 1½-year-old sons. Sheen is seeking joint custody.
Mueller has recently been seen working on a new reality show with Paris Hilton.
"Paris and the other girls on the show are going to Las Vegas and Brooke did not feel she could handle it now," Fiore said. "She was scared. We're all happy she will be in the facility and hope she will feel better."