Well, perhaps a plotline where fem Harry uses her unique magic abilities in ways the Lost Boys have never seen before. This could lead to her being both respected and feared within the group. She may also face challenges from outside forces that target her because of her association with the Lost Boys, and she has to fight to protect them and herself.
In some fem Harry and the Lost Boys fanfiction, a great plotline is her trying to bring a sense of order to the rather chaotic Lost Boys. Since she has a different background from them, she might introduce concepts like loyalty in a new way. She could also be involved in a plot where she has to choose between her old world (the wizarding world perhaps) and her new life with the Lost Boys, creating a real internal conflict.
Obviously, fem Harry is a main character. She brings her own set of skills, personality, and backstory into the story. The Lost Boys are also main characters. Each Lost Boy has his own distinct personality, like the more rebellious ones and the more sensitive ones among them.
One possible plotline could be fem Harry struggling to control her new phoenix - like abilities. For example, she might accidentally set things on fire when she gets emotional.
One interesting plotline could be her using her Metamorphmagus ability to blend in different situations at Hogwarts. For example, she might change her appearance to spy on the Slytherins when they are planning something devious.
One possible plotline could be their first encounter. Maybe Rhaegar, with his noble and somewhat mysterious air, meets Fem Harry in a forest. Their initial meeting might be filled with confusion as they come from different worlds but are drawn to each other's unique qualities.
One common plotline could be Fem Harry facing discrimination in the wizarding world after being expelled. She might have to prove herself outside of Hogwarts, perhaps by joining a group of outcasts and using her unique skills to gain respect. Another could be her uncovering a conspiracy related to her expulsion, like someone framing her to get her out of the way for some dark plot.
One possible plotline could be the son having unique magical abilities that are different from Harry's. For example, he might be able to communicate with magical creatures in a way no one else can. Another could be the son getting lost in a time - traveling adventure and meeting Harry's parents. Or perhaps he discovers a hidden part of Hogwarts that holds a great secret related to his family.
Perhaps Fem Harry is on a quest to find a lost artifact that was once owned by an Egyptian queen. Along the way, she has to navigate through ancient tombs, face magical traps, and deal with dark wizards who also want the artifact for their own evil purposes. This would be a great adventure - filled plot.
A really interesting plotline is when Fem Harry Potter discovers that Abraxas Malfoy has a secret power that could change the fate of the wizarding world. She has to decide whether to trust him and help him use it for good or to stop him in case he has ulterior motives. This creates a tense and engaging story full of moral dilemmas and unexpected alliances.
Well, perhaps in the fanfiction, the pregnancy could be a result of some sort of magical accident. For example, a misfired spell that has unintended consequences. Then, Neville and fem Harry would have to deal with not only the physical changes but also the emotional turmoil. They might seek help from their friends like Hermione and Ron, who could offer different perspectives on how to handle this situation.
One interesting plotline could be Fem Harry learning magic in a more unorthodox way under Sirius's guidance. Since Sirius is a bit of a rebel, he might teach her some spells that are not typically part of the Hogwarts curriculum early on. Another plotline could involve Fem Harry dealing with the challenges of being a female in the wizarding world, which has its own set of expectations and biases, all while having Sirius as her main support system. And perhaps there could be a plot where they go on secret adventures together, exploring parts of the wizarding world that are off - limits or forgotten.