She is not the first American female serial killer. A quick web search brought up several other women serial killers, some who were killing long before her.
Amy Archer-Gilligan - 1910-1917
Velma Barfield - 1971-1978
Judy Buenoano - 1971-1980
Nannie Doss - 1927-1954
Janie Lou Gibbs - 1966-1967
Jane Toppan - 1885-1891
...and probably the most rare, a pair of women serial killers.
Gwendolyn Graham and Cathy Wood - Jan. & Feb. 1987
She was unique in the fact she used a handgun. Most females seem to prefer poison. If her victims were strangers and not regular johns, that would also be a departure from the norm. Most women kill someone close to them, husbands/boy-friends/lovers and their children.
Her "lawyer" was more interested in his music and comedic careers and getting high than he was in being a lawyer. The stupid comments he made in an attempt to be funny were pathetic, but I guess we really shouldn't expect a pot-head to know what's funny. He should have been disbarred after this was released.
Aileen Wuornos was no where near an innocent woman and I believe justice was served with here execution, but her friends, family and lawyer deserve something.