One common theme is the idea of Fluttershy's friends supporting her through the pregnancy. Since Fluttershy is a very gentle and somewhat shy character in the My Little Pony universe, her friends would likely be there to encourage and assist her.
One common theme could be the idea of Fluttershy's friends supporting her during this new phase in her life. Another might be how Fluttershy adapts to the changes that come with being pregnant.
One common theme is self - discovery. Since Fluttershy is often portrayed as a shy character, in human form, she usually has to find out more about herself and her capabilities. For example, she might discover a hidden talent for art or music.
Nature also plays a role in many of these fanfictions. Given Fluttershy's connection to animals and nature, the story might be set in a natural environment where Fluttershy and the OC interact with various creatures and learn from nature together.
One common theme is the journey of Khushi through her pregnancy. It might include her dealing with morning sickness, mood swings, and the excitement of preparing for the baby. Another theme could be the relationship changes around her, like how her partner becomes more protective and loving.
One common theme is the struggle of their relationship in the face of this new situation. Since their relationship is complex, the pregnancy adds another layer of difficulty.
One common theme is friendship. Since Fluttershy is a character known for her gentle and friendly nature, many fanfictions focus on building a strong friendship between her and the reader. Another theme is personal growth. The reader often helps Fluttershy overcome her shyness, and in the process, both characters grow.
Another theme is mutual support. In many stories, they are there for each other in difficult times. Like when there's a problem in Ponyville, they combine their strengths. Applejack uses her physical strength and practical skills, while Fluttershy uses her ability to communicate with animals to solve the issue.
Friendship is a very common theme. Given that both Twilight and Fluttershy are characters from a show that emphasizes friendship, many fanfictions explore their friendship in different situations, like how they support each other through tough times.
Friendship is a very common theme. Her friends usually come together to help her, like in many fanfics where they use their unique skills to try and jog her memory. For example, Rainbow Dash might show her some of their flying adventures together.
Growth is also a possible theme. Both characters might experience personal growth. For Discord, he might grow in his sense of responsibility, and for Fluttershy, she could grow in her confidence as she prepares to become a mother. And all these themes would be explored in a way that is more about their relationship development rather than any inappropriate aspects.