4 afriend shes in bad shape with vascular eds, in hosp.dr said she needs to decide future/code status, she has the right at 20 to make own decision rite?

See below: If she is of sound mind and since she is legally an adult, she can make such decisions.

Yes: Very important - every adult needs to decide how he or she wants to leave this world (especially what he or she does not want done) before a severe event or illness happens. That means each adult should write his wishes down, give a copy to his doctor, and give another copy to a family member. Two forms are the advance directive and the polst (physician orders for life-sustaining treatment).