Joanna is one of the 13 fairies that I made up once upon a time (ha ha, no pun intended...ish) when I was a composing a (as of yet and probably perpetually) unfinished story about Sleeping Beauty. There's one for every month, plus one extra. They have all sorts of alliances and suchlike and are at war, and elemental, and all have weird names that are vaguely associated with their month names, function, or holidays therein. Joanna is the fairy of January. I went through a lot of January-sounding names before I settled on Joanna. She's a neutral fairy, loosely allied with Julia (July), whom she sort of looks after.