Lost into Smoke - X men Fan Fiction

Iris and Willow were sisters unlike most siblings. They were mutants. They were living in a small orphanage until Xavier came to get them. Iris chooses Xmen and Willow chooses the Brotherhood. Iris fears to think that she would have to go against her sister, but does Willow feel the same? This is my first fanfiction so please be nice.(Please note this is based solely on the movies)