Can a 13 year old make a decision of who to live with if her mom dies and dad is mentally disabled mom and dad are divorced and dad does not have custody?

The courts can make the decision to place a 13 year older in the right living situation that will better benefit their well-being. All the child needs to do is get the help of another older family member. It should be an easy process if the mom dies and the mentally-ill dad does not have custody.