Yeah, that's the main conflict so far. Since she's a woman her powers are less refined and she missed the date. (Remember she was worried earlier about taking the Prince back and finding her father since there was a possibility of missing the correct date.) I have no idea why she's trying to meet the Prince or why she hasn't tried time travelling again.
I think her dad mentioned to her before her dad died that he once travelled on the time the Concubine In (I'm not really sure of the concubine's name) was exiled. So she is hoping and waiting for the time the concubine to be exiled so she can meet his dad. My theory is that, maybe his dad time travelled on different time in that era without minding the year his into.

I'm confused about the timeline. This is ten years later.... But she says she lands ten years prior to when she wants to go in order to save her dad. But. Dad died ten years ago.... During the war. And ten years passed. The war is over.