Charlie Sheen's Estranged Wife Steps Out Without Wedding Ring

Credit: Michael Kovac/FilmMagic

Weeks after it was reported that she entered a stress-management program, Charlie Sheen's estranged wife Brooke Mueller made a surprise appearance Wednesday at the "lia sophia lanaya II collection preview" at Sunset Tower in West Hollywood.

Noticeably absent: Her wedding ring.

Mueller, 32, arrived around 7 p.m., skipping the line of press and mostly keeping to herself.

She was overheard telling a guest that she decided to come at the last minute before heading to a back table to try on clothes.

She stayed for less than an hour, picked up some jewelry and left.

Says a witness, "She wasn't social and was in-and-out of the event quickly."

Mueller and Sheen, 44 - who have 1-year-old twin sons - have been estranged since Christmas Day when the Two and a Half Men star was arrested after getting into a fight with Mueller in Aspen, Colo. He was later charged with second-degree assault, menacing and criminal mischief.

A hearing was set for July 12, but it has been postponed.