“I was born with a gold spoon in my mouth but I’m being murdered miserably? I’ll survive thoroughly and live a long life!”

I’ve been reincarnated as the younger sister of my favorite’s novel character who is destined to be poisoned by her step-mother at the age of seventeen. My brother is on an adventure with the heroine so I have to survive by myself.

Should we start with survival plans? First, be sure to behave myself around my step-mother and step-sister. Secondly, become close with children of influential families. Third, is… Um… Getting married?

To escape the fate of a miserable death, "I, Adriana, begin to approach the Prince of the Empire, the suspicious Master, and the suspicious Demon!"

I Dream of Health, Wealth, and a Long Life / The Goal Is to Become a Gold Spoon so I Need to Be Completely Invulnerable / My Goal Is to Live a Long, Healthy Life as a Golden Spoon / Mogpyoneun geumsujeolo mubyeongjangsuhagiibnida / Золотая ложка судьбы: Миссия выживание / Моя цель состоит в том, чтобы прожить свою жизнь с золотой ложкой! / 목표는 금수저로 무병장수하기입니다
https://teenmanhua.com/manga/the-goal-is-to-become-a-gold-spoon-so-i-need-to-be-completely-invulnerable/