April O'Neil is one of the few human friends of the Teenage Mutant Ninja Turtles.
Originally a lab assistant to the maniacal Dr. Baxter Stockman, April risked her life to save the Ninja Turtles.
In the many years of both the comics and cartoons April is a constant fixture of the Turtles universe. She is always there to help them out of any (and every) jam the boys find themselves in.
This casual look was what she wore during the time the Turtles, April and Casey Jones hid out on Casey's family farm when recovering from a near fatal battle with the Shredder and his evil Foot ninjas.
I love TMNT, but the humans in the line are way to short and stocky. They also lack pretty badly in the articulation department.
The turtles themselves are generally depicted as around 4-5 feet in height, making their figures fit well with most figures done in ML scale. So April needed some surgery to fix her overall height and dexterity.
The bulk of April is a Winfrey Rockbell from Full Metal Alchemist.
The hands and head were transplanted from the basic April in the TMNT line.
All in all a simple but effective recipe.