Your mother was a badass. Everyone knew it. She was strong, she fought well, she has saved milliona of lives. You were proud to call her your mother.
Now, she didn't mean to have you. Due to some hookup, she ended up with you. She was too late into finding out for an abortion, and she almost did give you up for adoption. She had an important job, one she can't be distracted from.
But you were so sweet. You barely cried. You came out so beautiful. How could she get rid of something that was so perfect looking, and risk you getting with someone who didn't know how to care for you?
So she juggled work and you. And did it well too. It wasn't easy but she did manage to do it, all with you being clueless about her kills for the first 12 years of your life. But when you were targeted by an enemy, the truth came out.
She trained you. She kept you safe, in your small cabin in the woods. And now, you were home alone, waiting for her to come home from a mission.