How about this:
Doerr is in critical condition at home from being abused by his mother. Trina goes to work, and Jessica goes on the camping trip. Baby is alone for a few hours till Grandma comes home. When Trina gets home, Doerr is alone and dead.
Jessica doesn't realize the seriousness of the situation till she calls her mom and finds out Doerr is dead. Hence, the "Mommy knows best" call. Calming her down. Since she is responsible.
Trina gets rid of the body on the way to the campgrounds.
EVERYONE is protecting Jessica.
Whoa.... there's a new angle..