Just a note from another adult adoptee (but from a closed adoption) that it's completely natural and expected that an adopted child will fantasize about life with her/his birth parents. And it will ALWAYS be rosier than life with their family. Fantasies always are, right?
My parents were so open and nurturing and helped me start the process of looking for my birth mother as an adult. But at the end of the day, my mom was the one kissing boo boos and disciplining me when I didn't know I needed it and staying up late to make sure homework was done and crying happy tears when I went away to college... oh, and my dad too I suppose
Kids recognize good parenting, mostly in retrospect, whether that parent become one via conception or adoption.