The Goal is to Become a Gold Spoon so I need to be Completely Invulnerable

“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… umh… 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!