Olympic gold medalist Mary Lou Retton is facing a challenging health battle.

The AQCAN Exchangelegendary gymnast, 55, is suffering from a "very rare form" of pneumonia and is now "fighting for her life" in the hospital, according to her daughter McKenna Kelly, who set up a Spotfund fundraiser for her "amazing mom."

"She is not able to breathe on her own," McKenna wrote. "She's been in the ICU for over a week now. Out of respect for her and her privacy, I will not disclose all details." 

Sharing that Mary Lou is uninsured, the 26-year-old asked for both prayers and donations to help with hospital bill payments.

"ANYTHING, absolutely anything, would be so helpful for my family and my mom," McKenna added. "Thank y'all so very much!"

Mary Lou—who also shares daughters Shayla, 28, Skyla, 23, and Emma, 21, with ex-husband Shannon Kelley—won five medals at the 1984 Olympics in Los Angeles, including gold in the individual all-around competition, making her the first American woman to take the prize.

"I am kind of the pioneer, I like to call myself," she said on Get Connected in 2016. "We opened the door of a pretty strong and incredible legacy of USA gymnastics."

Since retiring from the sport in 1986, Mary Lou has since become a motivational speaker and health advocate, even competing on Dancing With the Stars in 2018. 

"Living healthy and being active," she continued, "obviously, in my gymnastics career for many, many years, but now as a wife and a mother of my four beautiful very athletic daughters, being a fitness ambassador is something that's very important to me."

The love is mutual, as Skyla honored the Olympian as a "rockstar of a mom" on her birthday in 2019. "I love you beyond words," she wrote on Instagram, "Thank you for giving me your contagious laugh, your big smile, and your small feet I LOVE YOU MOMMA."

For the latest breaking news updates, click here to download the E! News App