When the reincarnated lady loves

I reincarnated into a body of a baby from a nobel family in a novel I read. After dying in a truck accident, heartbroken because of an unrequited love with my step brother who was getting engaged this week. But Wait, I was supposed to be a heroine in that novel ..not a villainess!! I swore I will not be naïve as my previous life and never fall in love ..But why is this handsome guy staring at me ?