The life of a young assassin. (Avengers fanfic)

Mila Romanov is the daughter of a Black Widow, Natasha Romanov. Before they could sterilize Natasha, they needed a new assassin that could match Natasha's skill and fierceness. From that sample, Mila was born by surrogate. Mila doesn't know anything about her parents, other than that they were both assasins. She goes on a quest to find out more about her life, along with her friends, scientists Nadia (wasp) and Ying.