Her heart was pounding in her chest.
The door handle was covered in blood and blood went on to the girl's hands.
Why is there blood on the door, she wondered, scared.
Then she opened the door, and paused, frightened that someone would see her.
At her feet, a body lay. Her sister, who was murdered my her parents.
This little girl found out her parents murdered her sister, because there was a bloody knife in her parents room. Which the girl used to kill her parents, the same way they killed her sister. Girl pressed the knife in heart.