One major theme is dealing with loss. Given Sirius's fate in the original story, his goddaughter in fanfiction often has to cope with his absence. This can lead to themes of grief, but also of finding strength in the face of it. Also, themes of magic discovery are common. She might discover new magical abilities or old family magic related to her connection to Sirius.
The theme of acceptance is also quite prevalent. She has to be accepted by the wizarding community, which can be difficult considering Sirius's reputation in some circles. At the same time, she has to accept herself and her place in the wizarding world. And of course, themes of adventure and mystery are common as she uncovers secrets about her godfather and the wizarding world around her.
In a particular fanfiction, Sirius Black's goddaughter is a powerful witch. She gets involved in a plot to save the wizarding world from a new dark force. This fanfic is full of action and adventure. It also has some really interesting relationships between the characters, especially how she interacts with the old friends of Sirius. It's a thrilling read for any Harry Potter fan.
The theme of freedom is quite important too. Sirius was locked up in Azkaban for a long time, and when he escaped, he was fighting for his freedom. Fanfictions often expand on this, showing his journey to fully regain his freedom and his place in the wizarding world, while also dealing with the prejudice against him because of his supposed crimes.
One common theme is family loyalty. Since she's a Black, her relationship with her family, including Sirius, is often explored. Whether it's defying the family's dark legacy or trying to redeem it.
A third theme could be the discovery of self - worth. In some stories, Sirius Black's wife starts off not fully realizing her own value. But through her relationship with Sirius and the experiences she has, she grows into a more confident and self - assured person. The fanfictions often use this theme to show her character development and how her relationship with Sirius was not only about love but also about personal growth.
The theme of redemption also shows up. Since Sirius had a somewhat 'tainted' reputation in the eyes of the Black family, some fanfictions explore if Orion could have played a role in his redemption or if Sirius could have redeemed the family name in Orion's eyes.
One common theme is the vulnerability of Sirius. Usually, he's portrayed as this strong, brave character, but when sick, he shows a different side. Another theme is the support from his friends and family. They often rally around him, highlighting the importance of those relationships.
One common theme is family conflict. Sirius rebels against the pure - blood mania and dark magic - associated ways of the Black family that Walburga represents. Another theme is the struggle for identity. Sirius is trying to be his own person away from the expectations set by his family with Walburga as a symbol of those family constraints.
One common theme is love. Often, the female character falls in love with Sirius Black, exploring the different aspects of romantic relationships in the wizarding world. For example, how they deal with the danger he's in and the secrecy required in their relationship.
One common theme is loyalty. Sirius was extremely loyal to his friends, and fanfictions often explore this aspect in different situations, like when he was in Azkaban but still held onto his love for James and his friends.
One common theme is unrequited love. Sirius might be jealous because he loves someone who doesn't seem to return his feelings in the same way. For example, he could be jealous of someone else getting closer to the person he has feelings for.