We're learning more about this terrible tragedy.
The Anger Management star teamed up with his OTHER ex-wife, Denise Richards, to throw Brooke a birthday party on Sunday.
"Charlie and Denise decided to throw Brooke a birthday party in honor of her 35th birthday. Charlie's kids with Denise, Sam and Lola, and his kids with Brooke, twins, Bob and Max, along with Richards' adopted daughter, Eloise will be in attendance."
Despite all the dramz the three have been through, sources say they "all get along extremely well," and continue:
"They want what is best for their kids, and truly love and support each other. Brooke is looking ahead to an exciting year, and is dedicated more than ever to being the best mom she can to Bob and Max, and knowing she has the support of Charlie and Denise truly means so much to her."
Sheen, Richards and Mueller may be an unlikely family, but they are still a family with all of the kids they share so we're glad they're doing well!
Happy birthday, gurl! Hopefully this will be your best year yet!
[Image via WENN.]