Spoiler alert!!
From what I read, her mother should have lived in different time (past). But she jumped to the current era and meet mc father. They got married and have 3 sons.
Unfortunately, (if I remember correctly) she can't stay in the current era because if she stay, something bad could happen and have to go back to her original era (she's pregnant with mc at this moment).
But instead of going back to her original time, she only turned back a few years, where she gave birth to mc and died. That's why, mc is older than her brothers.
Sorry if it's confusing. English is not my language.
It seems she's the youngest but her mother carrying her went to the past. And somehow she ended up in an orphanage in the past. That's why she is aged older than her older brothers. Apparently, she is stuck in this body because she is actually supposed to this age in the current timeline
Omg thx cleared up my doubts!
Oh !! Makes sense
Wait is she going to stay a child cuz what about the knight
Honestly the timeline is not matching up to me. Like if Mc really is the daughter. Then she needs to be the older sister. But it's being hinted that the mother passed away when she was pregnant. So like how can she be lost daughter??