Do you prouncounce it like Fran-Chesca or Fran-Kessa? Because I remember a read a book in middle school about a girl named
Francesca who went by Kessa which I really liked. Though Chesca is also nice too. There's also:
Franca (which I love)
Frannie Cessy (or Sessy) which I like a lot too
Frenchie
Frankie
Good luck!