DJ's little brother, Michelle, could also be involved in a cute way. She might not fully understand what's going on but could try to be helpful in her own innocent way, like bringing DJ a flower or something she thinks will make her feel better.
Perhaps the story could focus on DJ's own feelings. She might be embarrassed at first but then realize it's a normal part of growing up. She could write in her diary about her experiences and how she's dealing with the physical and emotional changes. And her friends at school could either be supportive or some might be a bit clueless about it all.
I think Hinata would be a great supporting character. Hinata is very empathetic and kind. She would be there to listen to Sakura's concerns and offer her quiet support. Also, Kakashi could play an interesting role. He might not fully understand what's going on but still offer his general wisdom and support to Sakura in his own unique, laid - back way.
Sonic could be a supporting character. He might be initially clueless about what's going on with Amy Rose but tries to be supportive in his own way. He could offer to do some of her tasks for her so she can rest. Tails could also be there. He might use his intelligence to find ways to ease Amy's discomfort, like inventing a device that provides heat for her cramps.
Definitely her sisters, Stephanie and Kimmy. Stephanie could be the fun and carefree sister who tries to cheer DJ up during the tough pregnancy days. Kimmy, on the other hand, might be the one with all the wacky ideas, like throwing a pregnancy - themed party for DJ. And of course, DJ's kids would also be important supporting characters, helping out around the house and being excited about the new baby.
The fanfiction might also explore the reactions of the other characters in Full House. Her family members, like Danny, Jesse, and Joey, could have different ways of handling the situation. Danny might be overly protective and want to make sure she has everything she needs. Jesse could be a bit more laid - back but still offer his support. Joey might try to use humor to make Stephanie feel more at ease.
Her best friend could be a main character. This friend might be the first one Lily tells about getting her period and could offer practical advice like which pads are the most comfortable.
Obviously, America would be the main character. There could also be some sort of selection committee or judges as supporting characters.
Bulma would likely be a main character. As Bulla's mother, she would play a crucial role in guiding and supporting Bulla through this new stage. She could share her own experiences and wisdom with her daughter.
Definitely his family members. His mother, for example, would be a crucial supporting character. She would be worried sick about him and would do everything in her power to take care of him. His father might also play a role, perhaps using his godly powers in some way to ease Percy's suffering.
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.