When women moved into the professions it started and then escalated in the 60's. Generally if a woman had already graduated from prof school,,MD, phd, whatever, and was licensed and had a career she kept her name. Some always did.
Actually lots of women complain they cannot find old friends due to the name changes. But professionally, best get married before all the degrees and licenses, otherwise it is a bitch to change and nobody knows you who went to school or trained with you.
Some women, including my Mother who was born in 1908, thought it was better to have a professional name and a married name to use socially.
It isn't entirely a feminist thing. Plus if you marry a man with a hideous name, some don't want to change theirs.