doctorslycat
(Forgive me if anything is out of character!!!!)
Willow and Andromeda were found by Julian Bashir when they were four years old, and in poor health. Julian took them into to heal them, and ended up adopting them when he became attached to them. Two or three years later, he discovers that they are half-human and half-mutant, and they each have a power. As their father, it's up to him to help. Years later, they're 15, and still trying to figure out the whole powers thing. A threat now faces DS9, and it's up to them to save the crew.