One plot idea could be that Sirius, who has a connection to Ginny through his friendship with the Weasley family, starts to mentor Ginny in some magical skills. He could share his knowledge of the more dangerous aspects of magic, like dark wizard - fighting techniques, which Ginny is eager to learn. This could lead to a strong bond between them as they train together.
Another idea is that Ginny discovers an old diary or item that once belonged to Sirius. As she delves into it, she starts to see his past in a new light and begins to communicate with a sort of spectral Sirius. Through this, they form an unexpected friendship and help each other solve some long - forgotten mysteries within the wizarding world.
A possible plot could be a time - travel story. Ginny accidentally travels back in time and meets a young Sirius Black. They team up to change an event in the past that has far - reaching consequences for the wizarding world in Ginny's time. Or perhaps Sirius, after his death, is able to communicate with Ginny in a way similar to how he did with Harry. He gives her advice on dealing with her relationship problems, like her feelings for Harry and how to handle jealousy among friends.
A third plot could be a story set during a big wizarding festival. Ginny and Bill are both involved in the preparations, but things start to go wrong. They must work together to fix the problems and save the festival. During this time, they might also have to deal with family drama as other Weasleys get involved, and through it all, their bond as siblings - in - law (or just as Weasleys) becomes stronger.
One plot idea could be that Arthur discovers Ginny has a special magical talent that she's been hiding out of fear. He then helps her gain confidence in using it. For example, it could be a unique form of wandless magic. Another idea is that they go on a magical adventure together, like exploring an ancient, forgotten wizarding site. There, they encounter strange magical creatures and have to use their combined knowledge and skills to get out safely.
One popular trope is time - travel. For example, Sirius might be sent back in time and meet a younger Ginny. Another is the 'protective Sirius' trope, where he looks out for Ginny in some dangerous situation. Also, the 'mentor - mentee' relationship is quite common, with Sirius guiding Ginny in magic or dealing with the wizarding world's challenges.
One plot idea could be that the reader is a new student at Hogwarts who is having trouble fitting in. Ginny takes the reader under her wing and shows them around. As they spend more time together, they develop a strong bond. Another could be that the reader has a special magical ability that only Ginny seems to understand, and they have to work together to figure out its origin and how to use it for good.
Here's a plot idea. Ginny becomes an Auror and is assigned to keep an eye on Draco who is still under some suspicion post - war. But as she observes him, she realizes he's not the same person he was. This leads to a series of interactions where they start to develop feelings. Another could be a story where Draco discovers a dark secret about Ginny's family that she doesn't know. He has to decide whether to use it against her or help her. And a third idea is a fanfic where they are both chosen for a special magical quest that only they can complete together, and during the quest, their relationship blossoms.
Well, a good place to start looking for Ginny Weasley and Sirius Black fanfiction is Tumblr. There are many fanfiction blogs dedicated to the Harry Potter fandom. You might have to dig a bit through the posts, but often they share links to great fanfictions. Also, some Harry Potter - themed Facebook groups might have members sharing their own or favorite fanfictions about these two characters.
Perhaps a plot where Ginny discovers she's pregnant during a time of unrest in the wizarding world. She has to be extra careful because there might be threats to her and the unborn child. It could also be about how she finds support not just from Harry but from her friends like Hermione and Ron. They could help her with everything from getting baby supplies from Diagon Alley to protecting her from any dark forces.
In a fanfiction about Ginny Weasley being kidnapped, perhaps she's kidnapped by a jealous rival. This rival could be envious of Ginny's relationship with Harry or her popularity at Hogwarts. As Ginny is held captive, she could use her own wits and magical skills to try and escape, while her friends are on a desperate search for her, leading to a tense and exciting story full of twists and turns.
A plot could revolve around Narcissa and Sirius in their Hogwarts days. They could be involved in a mystery within the school, like a series of strange disappearances of students. Since they are both from the Black family, they might have some inside knowledge that helps them solve the mystery, and in the process, form an unexpected bond.