腹違いの姉の婚約者を奪ってやりたいのに、王子様より姉の方がハイスペックで困るんですけど！！ (Associated Names)

I’m Catherine. I grew up as a commoner but it seems that the Duke will remarry my mother, and we’ll be welcomed into their House. Yeah, aren’t we so lucky? I’ll take advantage of this good fortune to snag a lord with good territory, money, and status! I was excited to put this plan into…