Try to separate the behavior associated with the disorder from your family member. You may need to explain that although you dislike and cannot accept the behavior, you still love the person. Frequently, sufferers feel that they are bad people and unlovable. They need to be reminded that these disorders are illnesses and that you recognize they are more than their illness. If hospitalization is required, recovery begins, not ends, at discharge.
Recovery is a process and it is possible to recognize different gains in each stage of the process.
It is not possible to judge improvement by eating or purging behaviors alone. Becoming assertive, communicating better and developing a better sense of self are important improvements to be noticed and supported. Do not try to be your family member's therapist. It will not be effective and it may seriously damage the relationship between you. No one else can truly fill the need of a loving parent, sibling or spouse.