April_ONeill

"April is a smart, strange sixteen year-old girl with an indie rock vibe.
The fact that April feels more comfortable with four mutant reptiles
than with her high-school peers should tell you a lot. When Splinter
realizes that she is "sensitive" to the same "universal vibrations"
that he is, he takes it upon himself to train her. Splinter knows that
the Kuno-ichi (the female ninjas) were actually considered the most
powerful and, over time, he will help her develop her abilities."

While in High School and continuing into College, She began seeing
and tutoring a hockey player named Casey Jones. The two both knew
of the Turtles and would even aid them in stopping crime.

April and Casey got an apartment together near New York University.
April became an assistant to Samuel Baxman not realizing he was really
Baxter Stockman in disguise. She helps him by writing journalism reports
for the school newspaper on the Turtles. Casey is a school Janitor, and
both of them get paid for their work. April still trains with Master Splinter
every day and spends time with the turtles almost every week end.


She can arrive in the park or any location by accident when she is
snooping around the Kraang Labs. April could easily fall through the
dimensional gate and wind up anywhere.

Summary is from TMNT Wiki