What was Wilma Flintstone's maiden name?
In early episodes, old friends of Wilma remember her as "Wilma Pebble." On the other hand, later episodes establish her mother as being "Mrs. Slaghoople." This presents two possibilities: either Wilma's maiden name was Pebble, but her mother got remarried to a Mr. Slaghoople somewhere along the way; or the early episodes are to be ignored and Wilma's maiden name is now officially Slaghoople.
Spinoff series and the Flintstones movies accept Slaghoople as being Wilma's maiden name.
As for Betty Rubble, her maiden name was McBricker in the TV series, but it was changed to O'Shale for the 2000 live-action movie The Flintstones in Viva Rock Vegas.
You might be interested in our biography of Fred Flintstone, and our collection of Biographies of Animated Characters and their Creators.