Ron might also have a strong reaction. He's Harry's best friend and Ginny's brother. If it's a big announcement, he might be really excited and start making jokes right away. For example, if it's about the pregnancy, he might tease Harry about being a dad. But if it's something that he thinks might be a bad idea, like a dangerous adventure they're planning, he'd be very vocal about his concerns.
Obviously Ginny and Harry themselves are very popular. Their kids, like James, Albus, and Lily, also often take center stage. Then there are the Weasley family members who are still around, like Ron and Hermione who are close friends of the family. Neville could also make an appearance as an old Hogwarts friend.
Another character that can be popular is Neville. He could be a teacher at Hogwarts when Harry and Ginny's children go there. His interactions with the kids, his teaching style, and his relationship with Harry and Ginny as old friends can all be interesting elements in the fanfiction. There might also be new characters created specifically for the fanfiction, like a mysterious neighbor or a new wizarding family that has some connection to Harry and Ginny's family.
Their friends from the Order of the Phoenix would be overjoyed and offer protection. Neville might give them some special plants that are good for a magical household with a baby. Luna would share her unique and sometimes strange but helpful insights about the baby's future.
Their children are often very popular characters. James, Albus, and Lily Potter can have their own unique personalities and story arcs. For instance, James might be the mischievous one like his father was at his age, getting into all sorts of trouble at Hogwarts. Albus could be the more introverted and studious one, grappling with the weight of his father's legacy. And Lily might be the brave and headstrong girl.
Some of their friends might also be a bit worried. For example, if there are still dark forces lurking in the wizarding world, they could be concerned about the safety of the baby. But overall, the love and support from their friends and family would far outweigh any concerns, and they would all come together to ensure a happy and safe environment for the new addition to the family.
Ginny might initially be heartbroken. She could retreat into herself, feeling betrayed and confused. In some fanfictions, she may cut off all contact with Harry immediately.
Obviously, Harry and Ginny themselves are very popular. Their relationship and how they interact as a married couple is often a central focus. Their children also draw a lot of attention, especially if they have unique personalities or magical abilities.
Parker would definitely react strongly. She and Eliot have a special bond, and she would be very protective of him. She might go into a bit of a frenzy, using her skills to either find the shooter or get Eliot the best care possible.
Asgore would be deeply affected. He has a complex relationship with Frisk, but ultimately he doesn't want harm to come to them. His reaction could be one of shock and regret. He might see this as a sign that his rule over the Underground has failed in some way. Flowey, depending on his state of mind in the fanfiction, could also have a strong reaction. If he has any positive feelings towards Frisk left, he'd be either very sad or extremely angry, and might try to manipulate the situation to his advantage.
The remaining Death Eaters could be the antagonists. Even though Voldemort is gone, there could be some who still hold a grudge against Harry and want to finish what their master started. They might track Harry and Ginny down as they run away, creating dangerous situations for the couple.