There's a really good one called 'Protective Sister, Brave Harry'. In this fanfic, the sister is a bit older and more experienced in the wizarding world. She steps in whenever Harry is in danger, whether it's from the likes of Draco or some of the darker forces. She teaches Harry a lot about self - defense and how to handle difficult situations.
A common plot element is the sister interfering when Harry is bullied. For example, if Draco is being mean to Harry, the sister will step in and put Draco in his place. Another is the sister helping Harry with his studies, especially in magic that can protect him.
One common theme is loyalty. The older brother is always loyal to Harry and will do anything to protect him. Another theme is family love. Despite the difficult situations they are in, the bond between the brothers is strong.
One popular 'harry has a protective older brother fanfic' is 'The Protective Brother'. In this fic, the older brother is always there to shield Harry from the bullies at Hogwarts and the dark forces that lurk around. He uses his magic skills and knowledge to keep Harry safe.
She could be a half - blood like Harry. Maybe her mother was a muggle - born witch and her father was a pure - blood wizard. This mixed heritage could give her a unique perspective on the wizarding world's issues regarding blood purity.
In many of these fanfictions, the theme of empowerment is prominent. The protective older sister is usually a strong - willed and powerful witch. She uses her powers not for self - gain but to protect Harry. For example, she may be an expert in defensive magic and use her skills to fend off attackers. Also, the theme of growth is there. As she protects Harry, she also grows as a person, learning more about herself and the world around her. Additionally, the theme of friendship often intertwines with her protection of Harry, as she forms alliances with his friends to better safeguard him.
A popular fanfiction in this vein is 'A Sister's Protection'. The older sister in this story has an uncanny ability to sense danger before it arrives. She is always one step ahead when it comes to safeguarding Harry. For example, she discovers a plot to harm Harry during the Triwizard Tournament and manages to thwart it. The story also delves into her own personal growth as she faces challenges while protecting Harry, making it an engaging read.
One possible plot could be that Draco's older sister, let's call her Astoria for example, starts to develop feelings for Harry while trying to bridge the gap between the Slytherin and Gryffindor houses. She might see the good in Harry that Draco refuses to acknowledge at first. This could lead to a series of events where she has to choose between her family's traditional views and her new - found respect and love for Harry.
In some fanfics, Harry might protect his younger sibling from bullies at Hogwarts. He could use his magic skills or his status as 'The Boy Who Lived' to intimidate those who try to harm his brother or sister.
Their relationship might start because of a shared interest in a particular subject, like Defense Against the Dark Arts. Maybe they both have unique insights on a certain spell or dark creature, and that sparks a conversation which leads to them getting to know each other better.