Akuyaku Reijou no Ane desu ga Mob de Ii node Shinitakunai

Giselle, the older sister of a villainous young lady, faces downfall or death at every turn. After remembering her memories from her past life, she begins re-educating her younger sister, Odile, the source of all evil, to prevent her from becoming a villainous young lady! What's more, Giselle's future fiancé is also a troublesome man who is certain to fall into the dark side...!? Giselle's struggle to live a peaceful life begins!

(Source: Comic Walker, translated)