Adventure is also a popular theme. They might go on a quest together, perhaps to find a lost magical artifact or to solve a mystery that has been plaguing Hogwarts for years. Their combined skills - Hermione's book - smarts and Lupin's practical experience - make them a great team for these adventures.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). There are a large number of Harry Potter fanfictions there, and you're likely to find some that involve Hermione and Professor Lupin. Another option is Fanfiction.net. Just use their search function and type in relevant keywords like 'Hermione Lupin' to narrow down the results.
I really liked 'Moonlit Paths'. In this fanfiction, Remus Lupin's werewolf side is depicted in a very unique way. It focuses on his internal battles and how he tries to find a sense of self - acceptance. It also has some great scenes where he interacts with the Hogwarts students and teaches them about the misunderstood world of werewolves.
One popular 'Professor Lupin and Hermione fanfiction' is 'A Different Sort of Magic'. It explores an alternate universe where Hermione and Lupin have a unique bond that goes beyond the normal teacher - student relationship. They embark on a journey together to solve a mystery in Hogwarts.
One possible plot could be Hermione seeking Lupin's help for some advanced magic study. Since Lupin is a knowledgeable wizard, he could guide her in a new area of magic, and during this process, a deep friendship or mentorship develops between them.
There are many great authors in this niche. Some popular ones might include those who have a deep understanding of the Harry Potter universe. But it's hard to name just a few as there are so many talented writers out there.
One common plotline could be Hermione seeking extra help from Professor Lupin in a difficult subject like Defense Against the Dark Arts. He might offer her special tutoring sessions, during which they develop a deep bond of mutual respect. Another could be them working together on a mysterious project related to the wizarding world's secrets.
In Remus Lupin werewolf fanfiction, the world - building around werewolves can be really unique. Authors create their own versions of werewolf communities, hierarchies, and cultures. Also, the way Remus's identity as a werewolf intersects with his role as a teacher at Hogwarts. It can lead to some interesting plotlines, like students discovering his secret and their reactions.
One great fanfiction is 'The Moonlit Path of Remus Lupin'. It delves deep into his struggles as a werewolf. It shows how he copes with his condition in Hogwarts and his relationships with the other characters. The author does an amazing job of portraying his inner turmoil and the way the wizarding world views him because of his lycanthropy.
One way is to show how Lupin's friends support him. James Potter's old friends could come together and create a magical protection charm around their house. This charm would be strong enough to keep Lupin's werewolf form at bay during the full moon and protect Tonks and the baby. Also, Tonks could be shown learning some new spells to protect herself and the baby in case something goes wrong.