'My Three Sons' Star Don Grady Had a Famous Sister Lani O’Grady Whose Life Ended at 46 — The Mystery of Her Death Remains Unsolved

"My Three Sons" alum Don Grady had a sister Lani O'Grady, an actress who died at 46. Although an autopsy was conducted on her body, the big question behind her death remained unanswered.

Don Grady's sister, Lani O'Grady, who passed away at 46, was famous for her role as Mary Bradford in "Eight Is Enough." In the 70s, she made an appearance in movies such as "The Love Boat," "The Kid with the Broken Halo," amongst others.

Lani came from a family of show-biz professionals. Her mother, Mary Grady, was a renowned agent for many child actors. Her brother, Don, was an original Mickey Mouse Mouseketeers; he also starred as Robbie in "My Three Sons."

INSIDE LANI'S DEATH

Lani was found dead at her mobile home by a neighbor. It was initially presumed that she died of natural causes but, the toxicology release showed that the actress died of multiple drug intoxication.

According to the Los Angeles County Coroner, Vicodin and antidepressant Prozac were discovered in her bloodstream. Lani had a distinguished history of addiction. In different interviews in the 1990s, she opened up about suffering from panic attacks.

The actress noted that she had sought help from many doctors who misdiagnosed her, and to manage the problems, she took Xanax, Valium, and Librium. Lani gradually became addicted to the pills and alcohol.

[Mary's] children, Don and Lani, were one of her clients.

The star noted in an interview that she drank two bottles of Chardonnay and took "tons of prescription pills" every day. However, in the 90s, she announced that she was free from the drugs thanks to a different medication regimen.

Still, in 1998, she went to a mental health ward of Cedars-Sinai Medical Center to obtain detox. She had become addicted to another prescription drug, Ativan before she later died.

LANI'S CAREER

Lani's interest in acting grew when she visited her brother on the "My Three Sons" set when she was 6. Her mother didn't encourage Lani's desires in the movie world because she was aware of the emotional effect acting could have on children.

When Lani became 13, her mother eventually gave in to her request to be put up for an audition. Initially known as Lanita Rose Agrati, Lani changed her name to Lani O'Grady after her role on "Eight Is Enough."

Unfortunately, Lani noted that she was constantly in and out of rehabilitation clinics after the series ended. Her struggles with panic attacks started when she was 18.

LANI'S BROTHER'S DEATH

Don was born on June 8, 1944, and grew up in San Diego. The "My Three Sons" star died at his home in Thousand Oaks, California, at 68. A spokesman for his family confirmed that he died of cancer.

Apart from acting, Don also had a passion for music. At 14, he was a top musician in high school who played the drums, accordion, ukulele, and clarinet. During his time in Hollywood, he made appearances in "The Rifleman" and "Wagon Train."

He also wrote songs for television, theater and movies. He wrote the music for Phil Donahue's talk show, TV series "The Kid-a-Littles" and the 1985 film "Girls Just Want to Have Fun."

DETAILS ABOUT LANI'S MOTHER

Mary, a famous agent for child actors, died at 96 at the Motion Picture & Television Country House and Hospital in Woodland Hills, California. Born Mary Biaggina Castellino, Mary was a child actor herself.

Mary married her high school sweetheart Lou Agrati in 1942. Her children, Don and Lani, were one of her clients. She also managed Penny Marshall, Nick Nolte, Tim Van Patten, Michael Clark Duncan, and Ellen Wheeler.