My Sister Switches My Child for Another

My sister pushes her daughter at a murderer so she can win the prize in a photography competition. After this, she even uses the incident and my name to extort the victim to pay an astronomical sum as compensation.

The victim stabs me to death in a fit of rage. When my son, who is brought up by me, learns the truth, he doesn't seek justice for me. Instead, he scatters my ashes in the sea and says, "My mother told me that I would've been the happiest child in the world if not for you taking the wrong child home back then."