The Secret of the O'Neils

What if the turtles weren't the only "family" members Eric Sacks was experimenting on? What if Mr.O'Neil had another daughter other than April' and to save her life, she too was experimented on as well? But in order to not let anyone have this amazing specimen, she was taken away from her family, and erased from their memories.
But now that Mr. Sacks is put away for good, and the Shedder is dead, she's back, and wants to go back to April. All of that while trying to understand the "side effects" of the mutagen, and feelings she has for a turtle?

A/N - Hi! Um, this is my first time writing one of these, so go easy on me. But don't feel like you can't give me feedback. I hope you'll give me constructive criticism and not plain out criticism. T~T Please play nice.
Anywho, I have been trying to look for fanfiction of this certain aspect but couldn't find any so I thought why not. I want it so why don't I just do it myself.
BTW, this is after the 2nd movie.
And it's a Leo x oc so, yeah let's get to it! I hope you like it, and I'll try to post twice a week depending on my schedule.