There could be several reasons. Maybe she has experienced some kind of trauma like being harassed on the street before. It could also be that she has social anxiety and is afraid of interacting with people outside. Another possibility is that she has received threats and is in fear for her safety.
One possible reason could be a misunderstanding. Maybe there was a miscommunication between Hermione and her friends, which led to them leaving her in the fanfiction. For example, if Hermione made a decision without consulting them, they might feel left out and decide to leave.
One possible theme could be the importance of women in a household. It could show how their presence and actions are vital for the family's well - being.
Perhaps the wife is frustrated with her husband's lack of empathy towards women. By turning him into a woman, she hopes he will gain first - hand experience of the discrimination, inequality, and different treatment that women often face. Also, it could be a form of revenge in a very unique and fictional way. If the husband has been dismissive or disrespectful of women in general, the wife might use this extreme method to teach him a lesson.
One possible reason could be a past traumatic event. Maybe she got lost in a dark place as a child, like a forest or a big, dark room. Another reason might be that she watched a really scary movie about the dark when she was young and it stuck with her. Also, some people are just genetically predisposed to be more fearful of certain things, and the dark might be one of those things for Jeannie.
Perhaps it was following a signal. There could be something in your house that emits a frequency or signal that the alien detected. It could be a simple electronic device or even something natural that gives off an energy that the alien mistook for something important. Or it might be that the alien is a bit of a mischief - maker, and it just randomly chose your house to have some fun and see how humans react.
It could be a matter of loyalty being tested. If Hermione is accused of something she didn't do, and her friends don't believe in her innocence right away, they might leave her. In fanfiction, the author might be exploring the idea of how fragile friendships can be. Her friends could also leave if they feel that Hermione has changed too much, for example, if she becomes too strict or too obsessed with a particular project or cause.
One reason could be for a costume party. If they are invited to a party with a theme like 'gender - bender' or a historical period where cross - dressing was common in the context of the party's theme, the wife might dress her husband as a woman. Another reason could be for a prank or a joke among friends. It could also be part of a performance they are doing together, like a skit for a local community event where the husband needs to play a female role.
Maybe Percy has shown some uncontrollable power that scares Annabeth.
It could be due to her family situation. For example, if her family is very overprotective, she may not have had many opportunities to interact with other children. Or perhaps there are family issues at home that are causing her stress and making it difficult for her to focus on building friendships. Additionally, her appearance or a disability might make her feel self - conscious and keep her from reaching out to others.
One possible reason could be that she feels she has outgrown the guild. Maybe she wants to explore new magic on her own and believes the Fairy Tail environment has become too comfortable and is hindering her growth.