She was 76.
You can view the list of her body of work at this IMDB link HERE.
One of the more interesting things I've read on Zelda was a few years ago in an interview Aintitcool.com did with her HERE in which she confirmed that Steven Spielberg actually DIRECTED portions of Poltergeist. She stated:
"I can tell you that Steven directed all six days I was there. I only worked six days on the film and Steven was there. Tobe set up the shots and Steven made the adjustments.You can read the backstory of the legend HERE on Wikipedia in the "Creative Relationship" section.
You’re not going to hear that from Tobe Hooper, you’ll hear it from Zelda, because that was my honest to God experience. I’m not a fan of Tobe Hooper."
Poltergeist remains one of my favorite celluloid ghost stories of all time and is something I try and watch once every Halloween season. (If you've never seen it, HOW DARE YOU, SIR! Please pick up the 25th Anniversary Edition RIGHT NOW through the Amazon links below. You'll be glad you did.)
We shall miss you, Zelda Rubinstein, but thanks to the magic of the movies, every October when we watch Poltergeist, we'll let you steel us against the evil spirits when you say "Let's go get your daughter back."