Legal Question in Family Law in California

A child who is over 14 has a statutory right to tell the court what they want as far as custody and visitation. It's not so much that a parent can "use" it, as the court is likely to listen to it. If the relationships are changing as the child grows up, and the child wants to spend less time with one parent, the other parent will likely eventually file to modify custody. At that point, either the family sorts out a new schedule, listening to everyone's needs and wants, including the child, or the court listens to both parents and the child and imposes what the court thinks is "in the best interest of the minor child."