One of the main themes is redemption. Audrey might have made some mistakes, and fanfictions often explore her journey to redeem herself in Mal's eyes and in the eyes of Auradon. Also, the theme of self - discovery is quite common. As they interact with each other, both Mal and Audrey learn more about themselves. For example, Mal might discover a more forgiving side of herself, and Audrey might find new strength in facing her past actions. In addition, the theme of acceptance is also there. They learn to accept each other's differences and past actions which helps in building a new relationship between them.
A common theme is acceptance. Since they start in a situation where they may not be aware of their sisterhood, accepting each other is a big part. Another is family secrets, as the discovery of being sisters often involves uncovering some hidden family matters.
I'm not sure if there is such specific fanfiction readily available. You could try searching on popular fanfiction websites like Archive of Our Own or FanFiction.net.
One common theme is friendship. Since they have a complex relationship in the original story, fanfictions often explore how they can overcome their differences and become friends. Another theme is redemption. For example, Audrey might be given a chance to redeem herself after her actions in the original story. And of course, there's the theme of love triangles, which can add a lot of drama to the stories.
There is a fanfiction that I really like which is titled 'Audrey's Redemption in Mal's Eyes'. It starts with Mal being very skeptical of Audrey after all the things that happened. But as the story progresses, they both grow and change. Mal realizes that Audrey is more than her past mistakes. It's a great read as it delves deep into their characters and how they can evolve in relation to each other. You can also look for fanfiction collections on Tumblr that are dedicated to Mal and Audrey. These often have a variety of different takes on their relationship.
No, it's not acceptable. Bullying in any form, whether in real life or in fanfiction, is wrong. Writing about bullying a pregnant person is especially cruel as pregnancy is a vulnerable time. Fanfiction should promote positive values and healthy relationships rather than negative and harmful behaviors like bullying.
Another option is Tumblr. There are often fanfiction recs (recommendations) on Tumblr blogs dedicated to the Descendants fandom. You might not find the full fanfictions directly on Tumblr in all cases, but the recs can lead you to other platforms where you can read the Ben Audrey Mal fanfictions.
Romance is also a big theme. Some fanfictions imagine a romantic relationship between Mal and Audrey. This could involve a slow - burn kind of story where they gradually fall in love, or a more sudden realization of feelings in the midst of some big event in the Descendants world.
You can try fanfiction websites like Archive of Our Own (AO3). There are often a large number of fan - created stories about various characters, including Mal and Audrey from Descendants. Just use the search function on the site and type in 'descendants Mal and Audrey' to find relevant fanfictions.
Redemption is also a theme. Audrey might be written as a character who needs to be redeemed in some way, and Mal helps her through that process while their relationship develops.