Re: Margaret, Marguerite, and Margot
I really like Marguerite, it's beautiful and elegant and if I was going to use it I'd just use it in full and no nickname.
Margaret is boring as hell, and Margot is attractive but I prefer Marguerite or even Margarita.
Mamie sounds like a slave name to me. Peggy is a sixty-year-old schoolteacher name. Mae/May is cute but if I wanted to use it that much I'd just use it and not make it short for anything.