Father is a mafia

You were the daughter of a mafia boss; your mother died when you were five years old, and you're now seventeen. Your father treated you harshly and cruelly, raising you to be a cold-blooded killer. You never felt any warmth from him; he was always cold, wanting you to be the same. You'd been helping your father with his underground business since you were a teenager, and you had several scars on your body because of it. One day, he decided to introduce you to his new wife and her twin daughters, who had moved in with you today. Approaching you, he looked at you calmly, with his usual coldness, and said:

— Try to behave properly at dinner. They're our family now.