Well, Sokka would probably make a lot of jokes about it at first, but then realize the seriousness of the situation. The other airbenders would be very confused as Aang is supposed to be their spiritual leader. They might question his judgment. As for the Fire Nation people, some might see it as a way to gain more power through the Avatar's connection, while others would be disgusted by Azula's actions considering her past deeds.
Katara would likely be shocked and initially angry. She has feelings for Aang and would be hurt by this unexpected turn of events. Zuko, on the other hand, might be conflicted. He wants his sister to be better but this situation is so out of the ordinary. Toph would probably be more straightforward and say what she thinks, which could be a mix of disbelief and amusement.
In a fanfiction where Aang gets Azula pregnant, one possible direction could be that Aang tries to bring out the good in Azula. He may hope that the pregnancy will be a catalyst for her to change. Aang could use his spiritual connection to the Avatar state to influence Azula positively. On the other hand, Azula might initially resist this change, but as the pregnancy progresses, she starts to develop maternal instincts that conflict with her previous power - hungry self.
If Aang gets Azula pregnant in a fanfic, it could be a very interesting plot twist. It might show a side of Azula that we haven't seen before, perhaps a more vulnerable side as she deals with pregnancy. And for Aang, it would be a huge moral and emotional struggle as he has to balance his duties as the Avatar with his new - found family situation.
Harry would probably be in a state of shock and disbelief at first. He'd be filled with a mix of fear, confusion and anger. Voldemort might be initially dismissive or see it as an opportunity to further his own dark plans. Hermione would be practical, trying to find solutions in books and magic. Ron would be more likely to be openly disgusted at first but might come around to support Harry as a friend.
The relationship would change drastically. Before the pregnancy, they were often at odds. But now, they are bound by this new situation. Zuko would probably be more involved in Azula's life, and Azula might start to trust Zuko more. They would have to communicate better to deal with the upcoming challenges of having a baby, like preparing a nursery, choosing a name, and dealing with the reactions of their family and the court.
In some fanfictions, Aang's connection to his past lives plays a crucial role. He could draw on the wisdom and skills of previous Avatars. They might guide him on how to defeat Azula specifically. He could learn a new bending technique from one of his past lives that gives him an edge over Azula's firebending, like a unique way of using water to extinguish her most powerful fire blasts.
The characters' reactions would be diverse. Harry, being the main character, would likely feel a great sense of responsibility. He'd have to face the judgment of both the wizarding community and the vampires. Hermione would be her usual studious self, looking for any precedents or magical knowledge to help. Ron would probably voice his concerns loudly, thinking it's a dangerous and strange situation. The vampire involved would have her own emotions, perhaps a mix of fear and hope for the future. And other vampires in the community could range from being supportive to being hostile depending on their beliefs and positions within the vampire hierarchy.
Jaime could be torn between his loyalty to his family (if we consider the complex family dynamics in the original story) and his new - found responsibility towards Sansa and the unborn child. He might try to find a way to make things right in his own way. Sansa would start to think about how this affects her political standing and her relationships with other characters. She may seek out allies who can help her through this difficult time, all while dealing with the emotional turmoil of being pregnant in such strange circumstances.
If Bella gets pregnant in the New Moon fanfiction, Edward's reaction would be intense. He loves Bella deeply, and this situation would be both a joy and a terrifying ordeal for him. He'd be researching every possible aspect of a human - vampire pregnancy. Jacob would be in a state of disbelief. His relationship with Bella has been complicated, and this would add another layer of complexity. He might try to convince Bella to leave the Cullens. The Cullen family would be focused on the medical and safety aspects. Esme would be motherly and nurturing towards Bella, while Rosalie might have mixed feelings, given her own past experiences with wanting a child. Charlie would be a mess of emotions, from confusion to anger to deep concern for his daughter.
Aang would be very happy and supportive. He has always been a friend to both Zuko and Katara, and he would see their union and the upcoming baby as a positive step towards more harmony in the world. Sokka might be a bit overprotective at first, especially towards Katara. But eventually, he would come around and be excited about being an uncle. Toph would probably make some sarcastic but also very endearing comments about the whole situation.
Another fanfiction could explore the challenges they face during Katara's pregnancy. Since Aang is the Avatar, he has many responsibilities. There could be a conflict where he has to leave for an important mission, but he doesn't want to leave Katara alone. Katara, being strong - willed, tells him to go and fulfill his duties. In his absence, she discovers new water - bending techniques related to pregnancy and childbirth, which she plans to teach other women in their community later.