In 1997, Saban's Entertainment produced a live fiction of the Ninja Turtles.
With one extra surprise, they added a 5th turtle and this one a female.
The story goes about the same when the turtles were exposed to the mutagen with a little twist with the 5th being found by a man who is a Shinobi (Mystic Ninja) named Chung I who adopted her, took her home to China and taught her the way of the Shinobi.
In a few years time, Chung I was killed by an evil Dragon Lord who escaped an enchanted mirror made by Chung I's magic, before his death, he advised his daughter to go to New York and find master Splinter to continue her Shinobi training,
When she arrived to the sewers, the original turtles didn't expect to meet a female turtle, they decided to name her 'Venus de Milo' and she became a member of the family.
What I'm disappointed about is that she was not added to other shows + movies been made.