"Why is she being like that?" well because:
1- She's a better person than you...no much explanation for that
2- She truly loves Sha Hu Rong, enough to see that he loves Yoo Chung and to let him go, wish them happiness
3- She's smart, she sees that there's no use in trying anything because he loves him a lot and won't change his mind just because she wants him too (● ̄(エ) ̄●)
4- Trying anything on Yoo Chung will result in your banishment from his life and likely death so... don't you dare try anything you jealous bitch and get it through your thick skull that he is not your possession or aything, you don't own him and he won't change his mind, especially for someone like you (︶︿︶)=凸
I literally spit my non-existing water when I read that message (⊙…⊙ )
Damn you go Nara (〜 ̄△ ̄)〜