Who is Kathi from Wasted: A Memoir of Anorexia and Bulimia and what is their importance?

On their first visit, Kathi, a nurse with the eating disorders clinic pronounces Marya's name correctly. This correct pronunciation clues Marya in that someone has been talking to Kathi about her. Kathi administers tests to Marya during her first visit to the eating disorders institute. From the results of these tests and Marya's vital signs, Kathi decides to admit Marya to Methodist Hospital. After Marya is dismissed from the hospital and allowed to move to California, Kathi tries her best to give the California doctors proper information to enable them to watch Marya closely.