What could i do to help my sister with her brain damage?

Be part of team: Traumatic brain injury has become a major part of our new society. I assume you refer to an acquired injury that has left her with problems. A major program of rehabilitation is needed with a team of therapists and helpers to get her back as functional as possible. There needs to be a consistent plan of action that all agree is appropriate. Helping her to be self sufficient is high goal.