@Lime-Tea - No, I don't think it's flipped. She specifically says that she can tell from the wound and bleeding on the right side of his chest that his heart was pierced.
Ha ha, I had to assume the knife pierce the right chest going diagonally to the left where the heart is located. Best logical deduction! I should be the sidekick in the manhua. Yes a 12 year old wouldn't have the strength and the knowledge where the heart is located. Thanks for the chapter