I don't think we can assume she's a villain. Just because she has 'another story' doesn't mean it's a story of villainy. She could be a bystander who gets involved in the events in Gotham in a positive way, like helping Batman or the police in some way.
It might be difficult to say for certain. Some fanfics are quite niche and not easily found. Maybe reaching out to specific fan communities dedicated to the relevant works or characters could be a good start. They might be aware of such a fanfic if it exists.
Ingrid faced a series of challenges and unexpected events. But it's hard to give a detailed account without knowing more specific details of your question.
Their relationship would likely become more protective. Gregorio would be constantly worried about Ingrid and the baby. He might start taking on more dangerous tasks himself to keep her out of harm's way. Ingrid, on the other hand, might feel a bit smothered at times but also appreciate his concern. They would also have to communicate more about their future plans, both as spies and as parents.
Perhaps the story starts with Ingrid being a new addition to a community where Dawn and Folsom are already a couple. But as she gets to know them better, a special bond forms between her and each of them separately. This could lead to a lot of internal conflict for all three as they navigate their new - found feelings, and there could be a journey of self - discovery along the way as they figure out what they really want in a relationship.
I don't know who created the 'Ingrid Never Ending Story'. There could be an individual writer, perhaps an amateur or a professional, who came up with this concept.
I'm not sure specifically what 'Ingrid Never Ending Story' is about as it could be a very unique or personal creation. It might be a story that features a character named Ingrid and has an ongoing, perhaps fantastical or complex plot that seems to have no end.
One common theme is the clash of different cultures. Since Ingrid is from a different background, her encounter with the Naruto world's unique culture often leads to interesting situations and misunderstandings at first, which then develop into mutual understanding.