
Oluris and Wilhelm are her cousins, right? She seems to call them brothers, but their mother isn't her mother. I'm confused. ( ̄∇ ̄")

I dont know about japan but in korea, if you are a female you adress older males usually as 'oppa' and older females as 'unnie.' THe litteral translation of oppa means older brother and the litteral translation of unnie means older sister.
If you are a male i korea, older dudes you usually refer as "hyung" and older females as "noona" which also mean older brother and sister.
You only usually use these terms if they are sorta close in age usually a year - 9 years sorta.

I wonder who is mother of 3 older princes. Since twins have incomplete blood because were born from Rurahel and thus could not make it through full transformation. Then if other princes could, it would mean that their mother must also have a power like king. And since only members of the royal family have this power, it would mean that marriages are made within the family. A little bit like incest? Maybe they'll explain it later. ╮( ̄へ ̄)╭
Why didn't she tell him at the beginning of meeting that it was a misunderstanding and she only sees him as an older brother? (〜 ̄△ ̄)〜