An unlikely love A bias narrator A shipper at heart

[I have decided to discontinue this story since I can't get back into the story to write it. I'm too far gone into the fan fiction realm.] Danny is a teenage girl with one secret. It's not a secret lover, secret talent or secret wealth. It's a secret weapon; she's an assassin. The only issue is that she doesn't realise this. Why is she doing this? Who is she doing this for?