Seeing this got me going around, and Debralee Scott who played MH's sister

died in 2005. Born in 1953.

Here is what IMDB had to say:
Ironically, she died in Florida shortly after moving there from New York City to help an ailing sister. One day she collapsed and was in a coma for several days but awoke in the hospital and seemed to be fine for a spell. She was released two days later on her birthday. No explanation was given for the coma, but she seemed fine and in good spirits. Three days later she went to take a nap and never woke up. Cause of death uncertain despite an autopsy. She was cremated.