The Duke's Darling Daughter-in-Law

I possessed the body of the no. 1 villainess, Ellie, who was a terrible person who tormented the Male Lead in the orphanage. I quietly waited until the day that the Duke would pick him up vowed to never get caught up in the novel, so she would not see the ugly ending that the villainess did, until... "I will also adopt the child next to him too... she will become my daughter-in-law." I was adopted along with the Male Lead! I can’t just do this? There’s a separate heroine! --- I have possessed the extremely cruel villainess who tormented the male lead during his childhood days in the orphanage. To change my fate, I decided “Just don’t do that,” but the pitiful boy kept getting beaten up by the other kids anyway, so I had to keep an eye on him even more! Then one day, his father's best friend the Duke, who had been searching for the male lead for 10 years, finally found the orphanage. “I'll adopt this child here. Oh, and the child next to him too.” Wait, why am I also getting adopted?! He wants me as his daughter-in-law for the male lead?!? What about the female lead?? — Just like in the original novel, the male lead joined his adoptive father in the war. He was supposed to return from the battlefield with the female lead, so I carefully prepared for a divorce and made a lot of money so I can live by myself! But… “Damian, did you come home alone? Did no one else come with you?” “Someone else?” Upon hearing my question, Damian’s gaze suddenly sharpened. “Ellie. are you looking for a man other than your husband?” “Huh?” “That's no good, I would probably kill that man out of jealousy.” I looked over to my father-in-law for help. “I also agree, Ellie. You shouldn’t betray your husband ever...”