@Dominions Son
Those are nick names, or diminutives, they are unlikely to be someone's legal first name. Personality/career will play a bigger role there.
Not always. I knew a girl in school who's birth name was "Trixie". And actress Barbie Wilde is her actual name. I knew several with that name later on also. It got some popularity in the 1960's after the doll came out.
A lot of the kids of the 1960's got some really weird names like that. I knew 2 sisters like that. "Moon" (short for Moonlight), and her sister "Star" (short for Starshine). But those were their actual birth names.
Do not forget the names of Frank Zappa's kids. The hospital refused to name his son "Dweezil", so he picked 4 names at random. Dweezil did not learn until much later his birth name was not what he was called. And his other kids were Moon Unit, Diva Muffin, and Ahmet Emuukha Rodan (yes, his second middle name came from a Japanese movie monster).
Strippers like a lot of people in the entertainment industries use stage names.
Mostly yes, but I am talking real name not stage name. I worked in that industry for several years, and got to know both. "Mary Jane" for example, who was Sophie. And "Jade", who was Nancy. But also a "Danielle", who did not know better and used her real name.
I have to disagree on Maggie.
I am married to a "Maggie", but the mental image the name normally brings up is that of a spinster schoolteacher.