My knight in red armour

You are Shiro's adopted younger sister. You also are an Galran experiment.

Backstory:
Takashi Shirogami And his father found you in a crashed Galran ship and they took you in. After Shiro joins the mission with Max and Pidge's father, you feel something calling you. That calling leads you to your lion, Lumiose. You travel space helping the rebels as much as you can but you get captured again. Where you encountered Shiro and Matt again. Sadly Shiro and Matt disappear. When you get saved, they don't know your secret.

But how will you keep it from those you love? And will they reject you or will they except you for what you are?

Main things you need to know:
(Y/n) means your name
(H/c) means hair colour
(H/l) means hair length
I'll add more later