Kushina would take care of baby Naruto very tenderly. She would make sure he is well - fed before sleep, perhaps by breastfeeding him or giving him a warm bottle. She'd also check his diaper and change it if needed.
Well, a fanfiction could explore how Minato and Kushina's love for each other is reflected in their care for Naruto. Their strong bond as a couple helps them create a loving and stable environment for their baby.
In fanfiction, Kushina might also interact with baby Naruto in a protective way when facing potential danger. Imagine a situation where some rogue ninjas are after Naruto for some reason. Kushina would put herself in front of Naruto without hesitation, using her chakra chains to fend off the attackers. And after the danger has passed, she would comfort Naruto, telling him that he is safe now and that she will always protect him.
One possible development for Naruto is that he begins to show signs of leadership. Even as a baby, he might gather the other village kids around him and lead them in some small play - adventures. For Kushina, she could develop a more nurturing side. She might start to think more about the well - being of the whole village because she realizes that Naruto will grow up in this environment. So, she could be involved in activities that improve the living conditions in the village, all because of her love for Naruto.
One great fanfiction idea could be about Minato and Kushina's daily life with baby Naruto. Maybe it shows how they take care of him, the little things like Kushina singing lullabies to Naruto while Minato watches with a loving smile. It could also include how they start to notice Naruto's unique chakra even as a baby.
One interesting scenario could be Kushina protecting baby Naruto from some hidden threats in the village. She might use her unique Uzumaki abilities to keep him safe.
One possible reason could be mind control. Maybe an enemy of the village found a way to manipulate Kushina's mind and make her turn against her own baby. Another reason might be a misunderstanding. For example, she could have been tricked into believing that Naruto was a threat to the village in some way.
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.
One interesting storyline could be Kushina teaching baby Naruto some basic ninja skills in a really gentle and loving way. For example, she might show him how to throw a kunai softly so he doesn't hurt himself. Another could be their interactions with the other villagers. Maybe Kushina takes Naruto around the village to introduce him to the different shops and people, which would be really cute as baby Naruto would be all wide - eyed and curious.