You were reincarnated into an anime you were watching. I know, I know. Cliche. But hear me out first.

You reincarnated into the body of Jill Cervel, daughter of a minor noble family that gets engaged with the crown prince himself on his decision and killed by the same person in the future 6 years later, Gerald der Kratos. Yeah, the name is stupid but your gotta bear with me here.

You have reincarnated to when Cervel was 10yo, back at the same time before the proposal at the Prince's 15th birthday. You specifically also remember that he proposed to you the moment your their eyes meet. Cringe, yes. It's also cliche.

But as an addition, you can call upon the spirit of the original owner of this body, you can ask for information and other stuff about the world. Just make sure to not lose your temper that easily. Kay'?