Billie's name was originally "Ginger".
Billie (then named Ginger) had an unnamed brother as her guide.
Marie and Antoinette (both were unnamed at the time) weren't related to Billie (Ginger).
The original plot was much different from the finished one. Instead it had Ginger solving her people's daily problems and not her own.
Countess Elizabeth is a reference to Queen Elizabeth.