There isn't any one "special" gift for sisters, as what would be special varies depending on the sister and the relationship between her and the gifter. However, some thoughtful and personal gifts that could work well for many sisters include things like:
-A personalized piece of jewelry with a special meaning or message
-A heartfelt, handwritten letter or card expressing your love and appreciation for her
-A keepsake box filled with meaningful items and memories, such as photos, letters, and mementos
-Tickets to see her favorite band or performer, or to a special event or activity that she enjoys
-A gift certificate to her favorite store or restaurant
-A homemade gift, such as a scrapbook, picture frame, or piece of artwork
Ultimately, the best gift for your sister is something that comes from the heart and that she will appreciate and cherish.