One common plot is Kushina finding Naruto in a different time or dimension. For example, she might end up in the future where Naruto has grown up and she gets to see the kind of person he has become. It's an emotional and interesting concept as she gets to witness all his achievements and the challenges he has overcome.
You can try websites like Fanfiction.net or Archive of Our Own (AO3). On Fanfiction.net, you can simply search for 'Kushina finds Naruto' in the search bar and it will show you a list of relevant fanfictions. AO3 also has a large collection, and their tagging system can help you narrow down your search to find exactly what you're looking for.
She might be overjoyed. After all, Naruto is her son. She could immediately rush to find him and embrace him tightly, tears of happiness streaming down her face.
One consequence could be a shift in the power dynamics. If Kushina is alive and now reunited with Naruto, they could form a powerful duo. This might make their enemies more cautious or even lead to new alliances being formed against them. Also, Naruto's morale would be greatly boosted, and he might become even more determined in his goals, which could speed up the overall plot development.
One great fanfic could be 'Naruto's Reunion with Kushina'. In this fanfic, Naruto discovers a hidden jutsu that allows him to travel back in time and he meets his mother Kushina. It's a heartwarming story as they bond and Kushina gets to see the amazing person Naruto has become.
The exploration of Kushina's past is also great. A good fanfic will show how Kushina was before Naruto was born, her relationship with Minato, and her life in the Uzumaki clan. This gives more depth to the story. In some fanfics, Naruto also gets to experience some of her memories, which is really interesting.
Another aspect could be that the fanfiction delves into how Kushina's presence affects Naruto's relationships with others. For instance, his relationship with Sasuke could be different. With a strong maternal figure in his life, Naruto might be more stable emotionally and be able to approach Sasuke in a more understanding way, which could potentially change the whole dynamic of their rivalry and friendship.
Well, one possibility is that Naruto would be overjoyed. He has always longed for his mother's love. He might spend days just talking to her, sharing all his experiences, from his training with Jiraiya to his battles against the Akatsuki. Kushina would probably be extremely proud of him and would start teaching him some Uzumaki clan jutsus that were passed down in the family. And Naruto's relationship with the village would also change. He would no longer be the orphan that everyone pitied. Instead, he would be the son of a hero, which could bring a whole new dynamic to his standing in Konoha.
Perhaps Naruto finds a way to travel back in time and prevent Kushina's death in the first place. He could use his Sage Mode or some other special ability to manipulate time. And then, by changing the past, he effectively'revives' her in the present. In the Naruto universe, there are all kinds of crazy powers, so time - travel isn't completely out of the question.
In some fanfictions, Kushina was sealed into Naruto through a complex jutsu. It might be a modified version of the sealing jutsu used to seal the Nine - Tails. The process could involve special incantations and chakra manipulations.