Haley would be a great supporting role. She could offer Peyton advice on pregnancy based on her own experiences. Lucas could also be included, perhaps he helps Nathan with getting ready for the baby, like fixing up a room in their house. And Brooke, she might be the one to throw a baby shower for Peyton and bring in all the fun and glamour to the story.
Family members would also play important roles. Peyton's parents might come back into the picture, either to support or cause some drama. Lucas's mom could be there to share her own pregnancy stories and offer practical help. Also, some of their more distant relatives could show up, bringing with them different family traditions related to pregnancy and childbirth.
Polly could be a great supporting role. Since she has a history with Piper, she could bring in some family - related drama. Also, Red would be an amazing addition. Her motherly nature towards Piper in prison could translate into her being a sort of mentor or a source of advice in their married life.
Renji could also work well. He's always been in the thick of things in the Soul Society. His rough - around - the - edges personality could contrast with the more subtle relationship between Ichigo and Lisa. He might be the one who accidentally stumbles upon their budding relationship and gives some comical reactions.
Kakashi would be an interesting addition. He could act as Naruto's advisor in matters of the heart. Since Kakashi has a good understanding of Naruto's character, he could give Naruto some valuable insights on how to handle his relationship with Shizune. At the same time, Kakashi's calm and collected nature could contrast with Naruto's more impulsive self, making for some engaging interactions within the fanfic.
Annabeth would be a great supporting character. She could be initially suspicious of Miss Martian, thinking she might be a threat to Percy. This would create some tension and drama in the story. Grover could also be included. His kind - hearted nature would make him open to befriending Miss Martian quickly, and he could act as a mediator between Percy and Annabeth when it comes to their relationship with Miss Martian. On Miss Martian's side, Martian Manhunter could play an important role. He could be the one who gives Miss Martian advice about her relationship with an Earthling, and also help her understand Percy's world better.
Definitely include Natsu. His enthusiasm and positive energy can add some light - hearted moments to the story. He could also be the one to accidentally push Cana and Gildarts closer together, like by getting them into a situation where they have to rely on each other. Lucy would also be a good addition. She's a good friend to Cana and can offer a different perspective on love and relationships, having her own experiences in the guild.
Rock Lee would be an exciting supporting character. His energetic and determined personality could bring some humor and motivation to the story. He could challenge Naruto to friendly sparring matches, which in turn could make Ino and Sakura cheer for them. Choji is also a good option. His loyalty to Ino and his friendship with Naruto could create some heartwarming moments. And Tsunade could play a role as well. As the Hokage, she could assign them important missions and also be a mentor figure, especially to Sakura, which would impact the relationship between Naruto, Ino, and Sakura.
Max's best friend could be a great supporting character. She could offer emotional support to Max during the pregnancy, give her advice on how to deal with Nathan, and be there for her when she's feeling scared or uncertain.
One idea could be that they face unexpected challenges during the pregnancy. Maybe there are health scares for Peyton or financial difficulties that they need to overcome together. Another plot could involve how their friends and family react to the news. Some might be overjoyed while others could be worried or even jealous.
I think Amren would be a great supporting character. Given her knowledge and power, she could provide valuable information about the pregnancy, especially if there are any magical or unforeseen elements. Also, Cassian could be there as a protector. He could train Feyre to be stronger during her pregnancy (in a safe way) and be on the lookout for any external threats. And Nesta could be a complex supporting character, starting off perhaps a bit jealous but then coming around to support her sister.