The Sapphire Witch (Marvel AU, OC)

This is one of my AU's of the MCU.
Wanda has a triplet, and her name is Kira. Instead of Kira being exposed to just the mind stone, she was able to be exposed to 3 of the six infinity stones. Power, Mind and Reality. This fiction takes place after Age Of Ultron and during Civil war. The thing is, Kira was still on a Hydra mission during Age Of Ultron. Wanda doesn't talk about Kira to the Avengers, mainly because she feels Kira will come out of hiding when she feels she should, and after Pietro died, Wanda finds it hard to talk about her family again. Until one day Kira decides to visit her younger sister... during one of the most difficult times for the Avengers.
What will happen?
Who is Kira?
How did she find Wanda?
What will the Avengers think of her?
Will she fight in civil war?
Which team will she join?
Team Captain America, or Iron man?