In the case of being privately retained by a parent’s attorney, the evaluator is primarily concerned with ensuring that the child ends up in the custody of the most capable parent. The child’s physical and mental well-being, as well as their balanced development, is central to the evaluation, and the attitudes of their parent figures are central to understanding what is best for the child.
This means that the primary client of an evaluator’s work is the child themselves. The efforts of psychological evaluation, interview, and review of past events all serve to provide the necessary background information for an informed evaluation. All of the evaluator’s analyses of the concerned parties are centered on seeing how both parents behave, as well as their relationship with the child.
The parent’s attitudes, capabilities, and past actions are all scrutinized to gain the most informed perspective on the family situation. I would say that an evaluator has the same responsibilities in regard to both parties and access them in equal measure.