Board Thread:Characters Discussion/@comment-4950212-20170322060231/@comment-173.79.220.228-20170409043537

She as good as adopted him. He was kicked out of his parents house after he turned 18 so he didn't need to be legally adopted, not sure if it'd even be possible. But he was still in high school (see beginning of this wiki page) for a while after his 18th birthday, and consider, if you have Netflix or a good way to do so, rewatching 3x07 "Memory is Your Image of Perfection", which has a big subplot about Melody as his "mother", and also watch the Travis moments in 3x21, when he graduates from high school and Melody and his mom get to meet. Those things might... answer a lot of your questions.