I'm Sure It's My Baby

After getting hit by truck-nim, she was reborn in another world as Claire, the eldest daughter of a baron. With a harmonious family, a lovely younger sister, and a modest estate, Claire had planned to live as an unemployed moocher and never work again. However, one night, she drunkenly slept with Duke Erich Clausener, rejected his proposal, and, when she returned home, found out that her younger sister had gotten caught up in something dangerous and they had to return to their territory. Her younger sister turned out to be pregnant and died giving birth to a son, Elliott. Five years later, in order to make Elliott her family's heir, she returned to the capital to find a husband. And everyone, seeing Elliott's appearance, assumes the boy is her child with Erich. How can she handle this mess?