The movie has been frequently described as a metaphor for Red Scare-era fears, but perhaps it's really a metaphor for being replaced by organically-grown alien dopplegangers. It's not the emanations of its metaphorical penumbra tha make the movie work - it's the general creepiness, the skill of its stars, and the intelligent construction. I think there have been 47 remakes, and not one got it right again.
So did she do anything else? Lots. Mostly TV towards the end of her career. The still at the top of this post is from 1960s' "Sink the Bismarck." - she played the assistant to the fellow who was supervising the naval battles from a room in a basement. She wasn't the love interest - wasn't that sort of picture - although she did leave the bunker with the Captain at the end of the movie, presumably for breakfast and a stiff drink. It was a small role, but she filled it with charm and intelligence.
Acting wasn't all she did; her imdb bio says:
Her wikipedia bio, updated with great speed, quotes her son as saying "she stepped off the bus very peacefully." Elegant to the end, then.
