jondrew lachaux is married to the teenager 's mother kellie phillips .
lachaux allegedly sexually assaulted the teen and she became pregnant .
parents went on road trip for months and left her to care for sister .
she gave birth alone in her mother 's bed and her little sister died .
lachaux told the teen she was not allowed to call 911 for help .
teen then hid in the body in a box under lachaux 's instruction .
lachaux kicked the teen out of the house and she slept at airport with baby .