I don't understand why she turned out to be like this. Is it because the MC spoiled her to...

I don't understand why she turned out to be like this. Is it because the MC spoiled her too much? Loving the person who raised you is just too abnormal. I would've beat the hell out of her if I was in MC's place. I would've beat her until she got back her senses. （￣へ￣）