A possible plot is that Lydia is pregnant by a character who is not very reliable. She then has to decide whether to raise the child alone or try to make the relationship work. There could be a lot of drama as she navigates her feelings, the other person's lack of commitment, and the practicalities of having a baby.
Perhaps in the fanfiction, Lydia is pregnant in a post - apocalyptic world. She has to find ways to protect herself and her unborn baby from various threats. This could involve teaming up with unexpected allies and facing difficult moral choices along the way.
One idea could be that they face challenges from their families who are initially not supportive of their relationship now that Lydia is pregnant. Another could be that they discover some sort of supernatural complication related to the pregnancy. For example, the baby might have special powers that start to manifest during the pregnancy and they have to figure out how to deal with it.
Maybe there's a mystery surrounding the pregnancy. Since they are in a world full of the supernatural, the baby could have some special powers even before birth. Some of the other characters like Scott and Stiles might suspect that there's something unusual about the pregnancy. They could try to investigate, which causes some tension between them and Lydia and Parrish, who just want to enjoy the pregnancy without all the scrutiny. But in the end, they all come together when they realize they need to protect the baby from some external supernatural threat.
One idea could be that they face unexpected challenges during the pregnancy. For example, Derek discovers a family curse that might affect the baby, and they have to find a way to break it. Another could be that Lydia has premonitions about the future of their child, which leads them on a journey to protect the unborn baby from a hidden danger.
Perhaps they find out they're pregnant unexpectedly. Stiles starts making all these plans for their future as a family right away. Lydia is more cautious, thinking about how this will change their lives completely. Their friends could also play a big role, some being super supportive while others might be skeptical. And they could have to deal with family reactions, like Stiles' dad being really excited and Lydia's parents having mixed feelings.
One idea could be that Lydia discovers she's pregnant and has to deal with the reactions of her friends and family. Maybe Stiles is the father and they have to figure out how to handle this new situation while also dealing with the supernatural threats in their town.
One possible plot idea could be about Lydia's journey through pregnancy. Maybe she discovers she's pregnant unexpectedly and has to deal with the reactions of her family and friends. For example, her parents might be disappointed at first if she's young, but then gradually come around to support her. Another aspect could be how she copes with the physical and emotional changes. She might find solace in a new friendship or an old acquaintance who has also been through pregnancy.
Perhaps a plot where Lydia and Beetlejuice accidentally swap personalities. This would lead to all sorts of comical and spooky situations. Beetlejuice in Lydia's body would have to deal with school and her family, while Lydia in Beetlejuice's body would have to handle the chaos of the Netherworld. They then have to find a way to switch back before it's too late.
One possible plot could be their journey of preparing for the baby. They might face challenges like dealing with family reactions. For example, Lydia's parents might have mixed feelings at first. Another plot could be how they balance their relationship while expecting. Scott might be overprotective, which could lead to some cute and also tense moments between them.
In the fanfiction, it could be that the pregnancy is a turning point in their lives. Lydia and Aiden could be part of a fantastical world where the pregnancy has some special meaning or power. For example, the baby could be prophesied to bring great change to their world. So they not only have to deal with the normal aspects of pregnancy like doctor visits and baby showers, but also protect the unborn child from those who might want to use its power for evil.
Perhaps the pregnancy is a result of some sort of magic gone wrong. In the Miraculous universe, there are many magical elements. So, a spell or an akuma's power could have caused Ladybug to become pregnant. This would lead to them having to figure out how to reverse it or accept it and deal with the consequences.