On May 13, 2018 Margot Kidder, who famously played Lois Lane opposite the late Christopher Reeve's Superman, was found dead by a friend in her Montana home.

The iconic actress was just 69 years old when she passed away "peacefully in her sleep," according to a statement from her manager Camilla Fluxman Pines.

Kidder, who was born in Yellowknife, Canada, dreamt of being an actress from a young age and she made sure that her dream came true in the late 60s.

"From when she was very young she was determined she was going to be famous," Kidder's sister, Annie Kidder, told CTV News Channel. "She was going to be an actress, and she wanted to be a star."

She eventually moved to Los appeared in a number of television shows and films like Black Christmas and Sisters.

But portraying journalist and Superman's love interest Lois Lane in the late 70s was the breakout role that turned her into a household name.

For many fans, no matter how much time has passed, no one will ever play Lane as well as Kidder did.

"Comic book films weren't treated seriously back then, they were considered throw-offs," Chris Bumbray, a film critic with joblo.com said. "In a way, I think the movies we have now wouldn't exist if it wasn't for Superman: The Movie and Margot Kidder, for me, is a big part of why that was so successful."

Kidder also starred in other blockbuster hits like 1979's The Amityville Horror and appeared in popular TV shows like Murder, She Wrote, La Femme Nikita, and Law & Order: Special Victims Unit.

Kidder's career was put on hold after a car crash in 1990 left her in debt and in a wheelchair for nearly two years. The accident worsened the state of her mental health and a few years later, she experienced a mental breakdown and was put under psychiatric care.

She was diagnosed with bipolar disorder, but she didn't let it get in the way of her work.

In addition to acting, Kidder became a vocal advocate for mental health as well as many political issues, including the North Dakota pipeline.

"I hope she's remembered as an advocate," said her sister. "She was passionate for a just society, and part of that just society was recognizing how hard the struggles can be with mental illness and that we can do something about it."

Kidder's sister insists that she was healthy and in a good place before she died, but according to the coroner's report, she wasn't doing so well.

Park County coroner Richard Wood confirmed in a statement that Kidder's death has been ruled a suicide. She apparently "died as a result of a self-inflicted drug and alcohol overdose."

No further details from the report will be released to the public, but Kidder's daughter Maggie McGuane told The Associated Press that this revelation doesn't surprise her and is relieved that the truth is out.  

"It's a big relief that the truth is out there," she said. "It's important to be open and honest so there's not a cloud of shame in dealing with this."

McGuane urged those suffering from mental illness and their families to reach out for help.

"It's a very unique sort of grief and pain," McGuane said. "Knowing how many families in this state go through this, I wish that I could reach out to each one of them.

Despite taking her own life, those closest to Kidder, including Joan Kesich, the friend who found her body, said she remained loving and true to who she was until the end.

"In her last months, she was herself "” same kind of love, same kind of energy," Kesich said. "The challenges that she had were very public. I want what I know about her to be out there because it was glorious. She was really a blazing energy."

If you or anyone you know needs help, please contact the National Suicide Prevention Lifeline at 1-800-273-8255.