This paperback was probably from ca. 1970. The well-off don't want their apple-cart upset by alien tech. Hero saves "Polly Ling" from an alien monster, which turns out to be her husband- she's an alien.
Bright New Universe by Jack Williamson.
I was looking for this book too and someone identified it yesterday here Seeking title / author of a story about alien first contact with Earth. The character is actually called Polly Ming not Polly Ling.