This is Arianna and her alter ego Nerissa. The thing that Nerissa is holding is called the Mystic Rod it's a lot like the Time Rod but also way different as well. Arianna was thought to be the New Sage of Light but now it's revealed that Arianna is the Sage of Mystics because her mother is Zeldalina's and Leene's aunt. Angella, Arianna's/Nerissa's mom, was born and raised in Aylagale but Angella fell in love with a man from Hyrule so she moved from Aylagale to Hyrule and lived peacefully until Ganondorf started a battle with Hyrule's royal family causing a war and killing Angella's husband so Angella fled to the Temple of Time where she was taken to the Chamber of Sages which is located in Aylagale and her two babies Arianna and Krystina were left in Hyrule. Arianna with Illia in Ordon Village and Krystina with their aunt Terra in Kakariko Village. Also Nerissa is based off of Windell which is Galelina's alter ego.

Arianna and Nerissa(c)(me)
Galelina and Windell(c)(one of my friends on DA)

Zeldalina and Aylgale(c)(another DA friend)
Zeldaleena(Leene)(c)(me and a friend on DA)