Naruto would probably be very friendly and kind. He has a big heart, so he'd likely greet her with a big smile and start chatting right away, asking her name and where she's from.
Perhaps the little girl is a prodigy but is being bullied because of her abilities. Naruto discovers her crying in an alley. He comforts her and tells her his own story of being an outcast as a kid. He helps her gain confidence. They might start training together secretly. The little girl could then use her new - found confidence and skills to impress the other kids in the village, all while Naruto watches with pride.
I suggest 'The Girl Who Changed Naruto'. Here, the girl Naruto finds has a very different view of the ninja world. Her ideals clash with Naruto's at first, but through their interactions, they both grow and eventually fall in love. It's a fanfiction that really delves into character development.
The plot could involve Natasha taking the girl under her wing. Maybe she tries to protect the girl from those who would misuse her powers. She could train the girl to control her powers, like teaching her self - discipline and combat skills related to using her powers effectively.
He could decide to protect the baby girl himself. Naruto has a big heart. He might see the baby as someone he needs to look after, just like how he was always looking out for his friends. Maybe he starts teaching her some basic ninja skills when she grows a bit older.
One possible fanfiction could be about Kushina finding Naruto in a situation where he's lost in a forest. Maybe she uses her unique chakra sensing abilities to track him down. It could be a heartwarming story of a mother reuniting with her son.
One possible scenario in this fanfiction could be that Naruto discovers an ancient and mysterious shrine in the forest. The shrine might hold some sort of power or secret. Maybe it has a connection to the Sage of Six Paths. Naruto, being his curious self, would likely start to explore it. He might find strange markings or artifacts inside that he has never seen before.
In this fanfiction, it may be that the little demon girl is lost in the forest and Natsu stumbles upon her. At first, she might be scared or hostile towards him, but as time passes, they develop a bond. Natsu could then take it upon himself to help her find her way back to her own kind or a place she belongs, all while they encounter different challenges like dangerous spells or other unfriendly beings in the forest.
Natsu might be a powerful wizard with a big heart. The little demon girl could be an outcast among her kind, which is why she's alone in the forest. There could also be other side characters like Natsu's friends who might later get involved in the story when he tells them about the little demon girl.
Natasha would likely be cautious at first. She has seen a lot in her life and new powers can be dangerous. But she would also be curious and protective.