@latisha_18 You mean Eugene right? She
Spoiler!
is actually twin sister of Prince Valentine and she was sent away to live with her birth fatter because she is illegitimate child just like Prince Valentine & current Emperor but only Empress Dowager, qst Empress who was Duke's mother & late Emperor knew.
I like to post spoilers for the stories I find interesting because I don't have much time to read novel due to busy schedule you will find me in most romantic historical manhwa comment sections