Romance is often a common theme. Maybe she falls in love with another character, and the story revolves around their relationship, with all the typical romantic elements like first meetings, misunderstandings, and grand gestures.
One common theme could be the new challenges they face as parents. Raising a baby is no easy feat, and in the fanfic, it might show how they deal with sleepless nights, feeding problems, etc.
One common theme could be the building of a new relationship, whether it's a friendship or something more. Another might be the exploration of their different personalities and how they interact with each other.
Love is a very common theme. Their passionate love for each other is often explored in great detail, from the initial attraction to the deep and abiding love that develops over time.
The theme of redemption can also be present. Maybe one of them has a past they're not proud of, and their meeting with the other becomes a turning point in their journey towards redemption. Their interaction during the meeting and afterwards can be a catalyst for positive change. For instance, Rowan might have been a bit of a loner or had a troubled past, but meeting Aelin gives him a new sense of purpose and a chance to be part of something bigger.
Adventure is another common theme. Fans like to imagine them going on exciting journeys, like traveling to different dimensions or exploring ancient ruins. This allows for a lot of creativity in the fanfics. For example, they could find a mysterious artifact in an old castle during their travels and have to figure out what to do with it. The adventure theme gives the opportunity to introduce various interesting characters and situations.
One common theme is the anticipation and excitement of starting a family. It shows how Aelin and Rowan prepare for the baby, like setting up a nursery or choosing names.
There are various platforms where you might find 'Rowan is female' fanfic. Websites like Archive of Our Own (AO3) are great places to start. Just use the search bar and type in 'Rowan is female' and you'll likely get a list of relevant fanfics.
One great Hogwarts female Rowan fanfiction is 'Rowan's Adventure at Hogwarts'. It follows Rowan as she discovers a hidden magical mystery within the castle walls. Another is 'Rowan and the Forbidden Forest', where she bravely ventures into the forest to save a lost magical creature. There's also 'Rowan's Friendship Bonds' which focuses on her relationships with other students.
If we assume that 'Ava and Rowan' novels are in the adventure genre, then themes could include exploration, facing challenges, and teamwork. Ava and Rowan might be exploring a new world or trying to solve a mystery together. They could face various obstacles along the way, which would test their friendship and their own capabilities. Another possible theme could be growth. As they go through different situations, they might grow as individuals and in their relationship with each other.
The plot also matters. It should be engaging, perhaps with new challenges for them to face as a couple. Like a new magical threat that they have to overcome together, which tests their relationship and makes it stronger. It could also explore their relationship in different settings or time periods that we haven't seen much in the original stories.