Dawn Lyn, a former US child star, is in a coma and "fighting for her life" after undergoing brain surgery, TMZ has reported.
The My Three Sons star, now 59, first stepped into the spotlight in the '60s and '70s as Dorothy 'Dodie' Harper-Douglas when she was just aged six on the CBS sitcom.
Her former co-stars have posted about her condition on social media, with Stanley Livinston - who played her on-screen brother 'Chip' Douglas - writing: "Just found out my little TV Sis’, DAWN LYN (Dodie), is in a COMA and fighting for her life. She had surgery recently to remove a brain tumor. Please pray for her to have a swift and full recovery.
"I took Dawn out to lunch a couple of months ago. We had a great time reminiscing about our MTS days. Dawn is one of the nicest human beings I have ever known. Thoughts and prayers also go out to her husband, John, at this time. This is devastating news!"
While Tina Cole wrote: "My heartfelt prayers go out to my "My Three Sons" sweet "lil' sis", Dawn Lyn (Dodie) and her husband John. Dawn is fighting for her life after undergoing brain surgery.
"I'm in touch with John and I will keep you all updated. Please keep her in your prayers as well."
Dawn's brother Leif Garrett told TMZ that his sister had not wanted anyone to know about the surgery but since it had been leaked on social media, he would "really appreciate everyone’s understanding that it has already been a difficult time having lost both of [their] parents and a cousin recently".
He added: "Please just keep my sister in your thoughts and prayers and respect our family’s privacy. Thank you."