Maid Of Honor Personal Gift

My sister is going to be my maid of honor in my upcoming wedding. I just have one problem. I don`t know what to get her for a gift. I dont have any other Bridesmaids, just her. I want to get her something personal and unique. For her wedding she had made me a scrapbook of us when we were growing up, it was very touching and personal. So if anyone has any ideas please let me know. Thank!