If the mother has been taking care of the child, she can apply for a change of custody. Changing the custody right can be decided by the parents of the child through consultation. If the parents fail to negotiate, the mother can go to court to sue for change. If the father of the child has custody but refuses to perform it, or the child is raised by the mother due to lack of time and conditions, the court will allow the change of custody. If the father of the child has the ability and willingness to support, the mother of the child violates the divorce agreement or court judgment and forcibly takes the child away for support. Mother's behavior is illegal, not only can't change the custody right, but also will be punished by law.