Comment by ryuuuuuuuuuuuuuuuu on Forget My Husband, I’ll Go Make Money - Chapter 120

It's Rine! But she had blond hair and green eyes coz she used her power to reach there through the medium she was viewing him.
Basically she can enter the world that she watches on water surface but when she enters that mirror world or alternate world, her hair and eye color change. And she completely forgot about that afterwards. 
She literally popped up out of nowhere and disappeared similarly and that's why Tarcan has been searching for that girl.