rehab center

Brooke Mueller is in rehab at Cirque Lodge in Utah, X17online can exclusively report.

Charlie Sheen's ex, who was arrested for cocaine possession last December in Aspen, Colorado, has been at the facility, located in Sundance, for several weeks.

Various reports claim Demi Moore is at Cirque Lodge, as well, and while those claims, we stumbled upon the news that Sheen's ex is there.

A source tells X17online exclusively:

    "Brooke is in treatment and doing fine. She doesn't seem too stressed or worried about it. You can tell she's been through this before. Honestly, she'll get through it and she knows there's a good chance this won't be her last time in rehab."

Our source adds that Brooke's parents are staying at a cabin near Cirque Lodge with twin sons, Bob and Max ... bringing them to visit their mom regularly. Mueller is expected to stay at the facility through the month.