The Perfect Swap, The Perfect Revenge

Claudia Drew takes the top exam score away from the girl who earned it, then uses a life-swap system to take the rest of that life as well, and the girl is tortured to death. The girl is Denise Lane, and she wakes up again in the days before the exam. She hands in a blank paper on purpose, which ends Claudia's plan to come first. After that she passes herself off as an heiress with money to spend, and Claudia comes toward her for it. Claudia runs the swap a second time, expecting a fortune and a marriage into a big family. What she gets is parents who want sons and will drain her for them, an old widower who expects five boys out of her, and a price from the system that comes back at a hundred times what she took.