The Goal Is to Become a Gold Spoon so I Need to Be Completely Invulnerable is a Manga/Manhwa/Manhua in english language, Fantasy series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

“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!