In a fanfiction, the author could show Hermione's jealousy through her actions. She might become overly critical of Luna's ideas, which are usually quite out - there. When Harry defends Luna, it makes Hermione even more jealous. She could also try to insert herself into their conversations or outings in a rather obvious and clumsy way. Like when they are planning to visit the Lovegood's place to see some magical artifacts, Hermione tries to invite herself along, not so much because she's interested in the artifacts but because she doesn't like being excluded from Harry's time with Luna.
One way could be to focus on Hermione's insecurities. Maybe she notices Harry and Luna having deep conversations about the afterlife or strange magical creatures that she doesn't fully understand. She starts to feel left out and her jealousy builds as she sees them growing closer in a way that she's not a part of. For example, if Harry and Luna start going on little adventures to study some rare magical phenomenon without her, she might start to resent their new - found bond.
One common theme is friendship dynamics. It shows how the relationships between the three characters can be strained when jealousy creeps in. Another theme is self - discovery. Hermione's jealousy might make her realize things about herself, like her own insecurities or unacknowledged feelings for Harry. And often there's a theme of miscommunication. Hermione might not communicate her feelings well, leading to more misunderstandings between her, Harry, and Luna.
One way to develop this in a fanfiction could be to show Hermione's inner thoughts. She's always been a top student, so seeing Harry get good grades might make her question her own intelligence. For example, she could start comparing their study methods. Harry might have a more intuitive approach while she's all about strict study schedules. This could lead to her feeling jealous and trying to outdo Harry in a friendly competition, which would add an interesting dynamic to the story.
A favorite scene in such fanfiction could be when Hermione finally confronts Harry about his actions that made her jealous. There's a lot of tension in the air as she tries to hold back her emotions but fails. Harry is left stunned and realizes how much he means to Hermione.
Well, Hermione could start arguing with Harry. She might say that he misread her actions or expressions. She could bring up past events to show that she has no reason to be jealous, like pointing out her own achievements and contributions which should make her above such petty feelings. And she may also question Harry's motives for saying so, wondering if he is trying to manipulate the situation or her emotions for some other reasons.
Harry might be really confused at first. He doesn't understand why Hermione is acting so strange. He might try to talk to her about it, but if Hermione is being stubborn, he could get frustrated. He could also be a bit oblivious and just think Hermione is being overprotective as a friend.
It can strain their friendship quite a bit. Hermione might start to distance herself from Harry. She could be short - tempered with him, snapping at him for little things that she wouldn't usually care about. For example, if Harry forgets to study for a test like he often does because of his other adventures, Hermione might be more critical than usual and less forgiving, which makes Harry confused and a bit hurt.
There are various reasons in fanfiction for Hermione to be jealous of Harry's girlfriend. One reason could be that she's jealous of the easy, romantic relationship Harry has with his girlfriend, while her own love life might be a mess. Also, she might be afraid that the girlfriend will come between their friendship. The fanfiction could show her acting out in small ways, like being a bit snippy with Harry or trying to find flaws in his girlfriend.
It could be a magical adventure fanfiction where they face challenges together and their soulmate connection helps them overcome obstacles.
One common theme is friendship. Writers often explore how the three characters' different personalities - Harry's bravery, Luna's eccentricity, and Hermione's intelligence - blend to form a unique and strong friendship.
There's a fanfiction called 'Bond Beyond the Common' which is quite interesting. It focuses on how Luna's eccentricity, Hermione's intelligence and Harry's leadership skills combine. They go on a journey to discover a hidden part of the wizarding world and their bond is tested and strengthened in different ways throughout the story.