His friends could also be divided. There might be those who immediately embrace Annabeth because they see her as an asset. For instance, if there are any students interested in architecture or strategy (which Annabeth is good at), they'd be thrilled. However, there could be some who are more territorial and feel like she's invading their space, which would create some interesting relationship dynamics in the fanfiction.
Some of Annabeth's friends could react with laughter and jokes, while others might be a bit flustered and not know how to act. It really depends on the personalities of the friends in the fanfiction.
They might be shocked. Percy is not an ordinary guy, and his abilities would be quite a surprise to them.
Grover would be super excited. He'd probably start bleating happily and immediately start thinking about all the great food he could eat at the wedding. Jason would be very supportive and offer his help in any way he could, like with security for the big day. Piper would be thrilled and would probably start planning Annabeth's bachelorette party right away. Leo might crack some jokes about Percy finally tying the knot but deep down he'd be really happy for them.
Grover would probably be really excited. He might bring all kinds of nature - related gifts for the baby, like a special plant that has protective powers. He would also be very protective of the baby, using his nature senses to detect any danger.
The students would probably be very excited. Percy has a lot of charisma and his tales of adventure would be really interesting. Some students might be a bit intimidated at first, but once they see his friendly side, they'd warm up to him quickly.
Some might be excited. They've probably heard a lot about Percy from Annabeth, so they are eager to meet him in person.
She might be really surprised at first. I mean, if it's unexpected, she could just stand there for a moment, not knowing what to do. Then she might blush a lot because she's embarrassed that it happened in public. But deep down, she could also be really happy that Percy made such a bold move.
Their friends at Camp Half - Blood would be overjoyed. Grover would probably be dancing around and playing his reed pipes in celebration. The other demigods would see it as a sign of hope, that love can thrive even in their dangerous world. They would start planning a huge party with lots of food and games.
Jason and Piper would be very supportive. They'd offer their help, like babysitting or providing resources. Piper might use her charm - speak ability to soothe the baby when it's fussy, and Jason could use his leadership skills to help Percy and Annabeth make important decisions about the baby's future.
She'd probably be shocked at first. But then her face would light up with joy. After all, she and Percy have been through so much together.