The Salvatores would probably be shocked. Damon might be initially angry, thinking Elijah has taken advantage of Elena. Stefan, on the other hand, would be more concerned about Elena's well - being and the implications of a half - vampire, half - something - else baby. He'd want to make sure she's safe.
The Mikaelson family would have a complex reaction. Klaus might see the baby as a way to gain more power or an heir to the Mikaelson legacy. Rebekah would be jealous at first but then might become protective of Elena and the baby. Kol would be intrigued and might cause some trouble just for the fun of it while also having a soft spot for the situation.
In this fanfiction, Elena's family may initially be shocked, but then quickly come around to support her. They could start making plans for the baby's future, like setting up a safe place to live. Elijah's family might have a more complex reaction. The elders might see the pregnancy as a sign of change in the family's power structure. Some younger members could be excited and look forward to having a new family member, while the more conservative ones may be skeptical and try to interfere in the pregnancy for their own reasons.
Elena's friends and family might be a bit wary at first. After all, Elijah is from a different world. Her aunt Jenna might be concerned about the implications of this marriage for Elena's future. However, her friends like Bonnie and Caroline could come around once they see how much Elijah loves Elena. For Elijah's family, some might be happy to see him find love, while others, who are more traditional or power - hungry, might see Elena as an outsider and try to break them up.
Well, first of all, Elijah would be by Elena's side all the time. He would help her with her daily needs, like getting things she needs or helping her move around when she becomes less mobile during the pregnancy. He would also share his knowledge of the supernatural world with her, so she can better understand what might be happening to her and the baby, and together they can prepare for any challenges that might come their way.
They might also face a lot of internal conflict. Elena may struggle with the idea of having a child so young, especially considering the chaos of the supernatural world she's in. Elijah, on the other hand, might have his own doubts about whether he can be a good father given his vampire nature. This could lead to some tense moments in their relationship.
Damon would likely make sarcastic remarks at first but deep down be happy for them. He and Bonnie have a long history, and he'd come around to being supportive. Elena would be very emotional. She'd be there for Bonnie, offering advice based on her own experiences, even if they were different in nature. The other witches in Bonnie's coven might be a bit worried at first, fearing that the pregnancy could disrupt Bonnie's connection to magic or put her in danger from other supernatural forces.
Rebekah's family has a long history of complex relationships. Her mother, if still around, might see the pregnancy as a way to strengthen their family's position in the supernatural world. However, some of her siblings like Kol might be jealous or feel left out. On Stefan's side, his vampire nature might make his family worry about the implications of having a half - vampire child. They would be concerned about how to raise a child in their world of danger and secrets.
Sirius's friends, like the Marauders, would be extremely shocked. They would probably be very concerned about Sirius as they know his feelings towards Bellatrix as an enemy. They might try to convince him to break away from the situation, thinking it's some sort of dark plot against him. James, in particular, would be very protective and would want to figure out what's really going on.
Tessa's family might be overjoyed at first. Her mother could start knitting baby clothes right away and her father might start planning how to convert a room into a nursery. They would offer a lot of advice based on their own experiences.
Gunther's family might be overjoyed. They could be very traditional and start preparing all kinds of old - family - recipe baby foods right away. Cece's family, on the other hand, might be a bit more cautious at first, but then quickly warm up to the idea and start knitting baby blankets.
The Stark family would likely be horrified at first. Sansa's father was beheaded by the Lannisters, and there is a long - standing feud between the two houses. Her brothers, if they were alive, would be very angry and might see it as a betrayal. The Lannisters, on the other hand, would also have a mixed reaction. Cersei would probably be furious, seeing it as a threat to her power and influence. Tyrion might be more understanding and could potentially try to mediate between the two families.