The Unknown Daughter

What if Oliver Queen had a daughter? She used to live with her mother Samantha, until she got taken to a laboratory on an island called Lian Yu. Her name is Ellie Clayton and she's fifteen years old, what happened to her and why has she gotten taken to a laboratory and especially on Lian Yu? Where her father Oliver Queen and his father become shipwrecked there, what would happen if Oliver finds her, what will he do? Will they be reunited as a family and did Oliver know about her? (Read to find out! And does anyone know of a good app where you can make good book covers on a mac book, if so that would be quite appreciated, Thank you!)