As Maryon grew older she began suffering from severe depression. In 1935 she attempted suicide by swallowing poison. She recovered but often talked about taking her own life. Maryon and her husband Ross lived with her parents at 1818 S. 2nd Street in Alhambra, California. Sadly in February of 1951 her beloved mother Eloise Aye died. Maryon had numerous health problems but she dreamed of acting again. She became despondent when she did not get a television role she auditioned for. On July 10,1951 Maryon, her husband Ross, and their dog went house hunting. That evening they checked into a Culver City motel. Maryon was very depressed and swallowed a handful of bi-chloride of mercury tablets. Her last words to her husband were "I dropped one of the tablets on the floor and I'm afraid the dog will get it". She collapsed and was taken in an ambulance to LA's General Hospital. Maryon spent eleven days unconscious in the hospital and passed away on July 21. She was only forty-eight years old.
The official cause of her death was suicide. Her father, James Aye, told police that she was suffering from uremic poisoning. Maryon's husband Ross said that she had a "chronic illness" but that he never took her threats of suicide seriously. In an interview Maryon had said "Friends console me by talking about what I used to be but I'm sick of living in the past." Maryon was buried next to her mother Eloise at Forest Lawn Memorial Park in Glendale, California. The epitaph on her headstone says "Maryon Eloise Aye Our Beloved Daughter". Her grave is located in the Tranquility section. Many other stars are buried at Forest Lawn including Elizabeth Taylor, Carole Landis, and Jean Harlow. Maryon's father James H. Aye died on January 12, 1961 at the age of 80. He was buried at Forest Lawn in Hollywood Hills. Her widower Ross Forrester died on December 22, 1964 at the age of 66.