In my search for nicknames for some of the great names you ladies gave, I found this link and thought you all might like it: https://genealogy.about.com/library/bl_nicknames.htm
It's a listing of common nicknames used by previous generations and their traditional given name equivalents. Good stuff!
Re: s/o: Older nicknames
(read it. you know you want to.)
anderson . september 2008
vivian . february 2010
mabel . august 2012
Daisy would come from Little Women where Margaret, called Meg, named her daughter Margaret and they called her Daisy.
I think I once read in a name book that Margaret is one of the names with the most nick names and variations.
Edit: And I do attribute it to this book and not an already existing nickname because they named the boy twin John, after his father, and called him Demi (French for little). You'd have to know the book, but they were trying to be creative about it.
I read somewhere that alot of the seemingly random nicknames, like Peggy for Margaret, came from the Victorian era. They apparently liked to rhyme. So Meg became Peg, and Meggy became Peggy. Same deal with Will/Bill, and Rob/Bob.
I might be wrong, but that is what I found when I looked it up one day.
I have no clue how they got Daisy though.
Every time I see you write that you go by Effie, I immediately think of Mrs. Doubtfire... Euphegenia Doubtfire
She (he) describes sex between her and her "husband" and the "husband" refers to her as Effie...