Birthday Wishes for Sister: Sisters are the most adorable members in every family. When it comes to their birthdays, it becomes our responsibility to bring smiles on their faces by wishing them a warm birthday message. Let your sister know how special she is to you. Your hearty birthday wishes to your sister will double the joy of this day and make her feel the warmth of the relationship that every sibling share. Here are some examples of wonderfully crafted birthday wishes for your sister.