I hate people who are sticklers for annoying details of no consequence, but this is my chance to be one! It is my understanding that Mrs. Brown was never called "Molly," and that the nickname was fabricated by either a reporter or the writer of the play about her. As I understand it, "molly" was a derogative term in those days for a hooker or easy woman. Kind of like "broad," and few if any would willingly adopt it as a nickname. Of course, the whole world now knows her as "Molly" Brown.
What is the cumulative wisdom of this group on this? I'd love to hear.