What experience have you had working with a Psychiatrist? What can we expect,and how can I prepare for Mom's visit?

A Geriatric Assessment Clinic recently diagnosed Mom as having a Personality Disorder. Today, she'll be meeting a new Psychiatrist for the first time, by referral. They sent a huge Questionnaire for her to fill out beforehand, as a way to become acquainted with her. She confabulated many of the answers. I have begun refuting some of them, to portray a truer picture of the "real" Mom, as we have known and witnessed over the past 49-51 years. My sister collaborated with me in this process, with her observations. Will our added input be useful in this process?