That can contribute to how your sister turned out. Often with narcissistic parents, they don't recognize the child's need to have their OWN identity. The child MUST be an extention of them. This can create an offspring that is the same and may develop strong narcissistic traits. And, ofcourse they consider anyone who doesn't view the world the same way, have the same opinions they deem that other as "a difficult person" and "it's always that other person's fault" not theirs. And ofcourse the ongoing need for "drama, drama, drama". Without it, they are literally "bored".

That is what my brother said to me, my sister's life has been basically about creating and engaging in "drama". It's VERY negative and emotionally abusive and manipulative and controlling.