The fanfiction could focus on the reactions of their friends and family. Nick's friends might be worried about how a half - Grimm, half - whatever - Adalind - is child would turn out. And Adalind's side might have their own issues. There could be a lot of drama around the pregnancy, like false alarms, or threats that seem to target the baby specifically. And all the while, Nick and Adalind are trying to figure out their new roles as parents and strengthen their relationship in the face of all these difficulties.
They may also struggle with preparing for the baby's future. They need to think about things like education in a world where the baby will be half - Grimm and half - Wesen. Do they raise the baby in the human world or among the Wesen? These are all interesting plot points for a fanfiction.
Another aspect could be the emotional journey. Nick might be initially worried about how to be a father, especially considering his dangerous life as a Grimm. Adalind, on the other hand, could be conflicted between her past actions and her new role as a mother - to - be. Their relationship could be put to the test as they navigate through these complex emotions.
In this type of fanfiction, perhaps Nick and Adalind decide to start anew in a different place away from all the chaos of the Grimm - filled city. They build a home together, and Adalind starts to teach Nick more about the deeper secrets of the Wesen world that she has known for so long. Their marriage could be a symbol of unity between two different worlds. However, they may also face opposition from some traditionalists in both the Grimm and Wesen communities who don't believe in their union.
Nick would likely become more protective. His Grimm side might make him extra vigilant about any potential threats to Adalind and the baby. He could start to see the world even more in terms of safety for his family.
Maybe in the fanfiction, baby Diana gets kidnapped by a powerful Wesen who wants to use her powers for evil. Nick and Adalind team up with some unlikely allies, like a reformed Wesen criminal. They embark on a dangerous rescue mission, facing numerous challenges and traps along the way. During this time, they also learn more about each other's pasts and grow closer as a couple.
One possible plot could be that after years of a tumultuous relationship filled with mistrust and power struggles, Nick and Adalind finally realize their true feelings for each other. They decide to get married in a small, private ceremony surrounded by their closest friends and family. However, their past foes try to disrupt the wedding, but they overcome all the obstacles together and start a new chapter in their lives.
Nick and Adalind's relationship in such a fanfiction could be full of growth. Since they are married, they would be more open with each other. Adalind could finally feel secure in her relationship with Nick. She might share all her secrets about the Wesen world with him without hesitation. Nick, on the other hand, would be more protective of Adalind. They would start to plan their future together, whether it's about building a new community that is more inclusive of both Grimm and Wesen or just living a quiet life away from all the drama. Their relationship would be a journey of discovery, learning about each other's true selves and loving each other despite their differences.
They would become more committed to each other. Their relationship would likely shift from a more tentative or even adversarial one in some cases to a more unified front. They would support each other more openly.
One possibility is that after many adventures and overcoming numerous obstacles together, Nick realizes he can't live without Adalind. He plans a grand and romantic gesture, perhaps in a place that holds special meaning for them. He tells her how she has changed his life and how he wants to build a future with her, and then pops the question.
One great adalind and nick fanfiction is 'The Unlikely Bond'. It explores their relationship in a unique way, with a lot of character development. Another interesting one could be 'A New Beginning' which takes their story in a different direction from the show.