One way could be through some sort of time - travel or alternate reality plot. For example, if there was a situation where Captain Marvel went back in time and became involved with Peter Parker's father, or if an alternate reality had different rules of genetics and relationships. Another way could be a magical or alien - influenced situation where Captain Marvel was somehow magically linked to Peter Parker's creation in the fanfic world.
In fanfic, the writer could create a backstory where Captain Marvel was experimented on by some evil or well - meaning scientists. The experiments could have led to her having a connection to Peter Parker's family. Maybe her DNA was somehow merged with that of Peter's mother in the fanfic's universe. Or perhaps in a parallel universe, the characters' origins are rewritten so that Captain Marvel ends up in a situation where she gives birth to Peter Parker. There are many ways to twist and turn the story to make this relationship work in a fan - created narrative.
Fanfic writers have a lot of creative freedom. They could write a story where an interdimensional event brings Captain Marvel to a world where she meets Peter Parker's father at a young age. They fall in love, get married, and she becomes pregnant with Peter. Or maybe there's a cosmic entity that manipulates events so that Captain Marvel's life path intersects with Peter Parker's family in a way that she becomes his mother. It could also be a story of a future - gone - wrong where Captain Marvel travels back in time to try and fix things, but ends up in a situation where she has to take on the role of Peter Parker's mother in order to save the world in a different way.
Chapter 331, ", The Great Battle", is the clearest early answer because the buildup finally cashes out in a real clash. The setup is At the moment, this firepower proved immensely effective., but the pressure keeps building through Under heavy artillery bombardment, the unprotected Sentry Mecha in.... Once the chapter lands on They could retreat no longer;
Chapter 269, ", The West Coast of the Continent", is the clearest early answer because it turns Alliance's situation into a concrete plot event. The chapter turns that into something concrete by moving from Regarding the increase in death penalties, Gu Hang was somewhat... to Now, with the sudden replacement by public servants cultivated by the....
Chapter 218, ", do you actually realize the seriousness of the matter?!", is the clearest early answer because it turns Cohen's situation into a concrete plot event. It opens with He had lost an arm, indeed, but he was honed through the miraculous... and closes on The newly built wooden house on their property was not small.. The key payoff is that the chapter closes with Milia Derong slammed her hand on the table and demanded, "All these are evasive answers!
Chapter 224, ", A Thought of Union Arises", is the clearest early answer because it turns Polar Industrial Group's situation into a concrete plot event. It opens with Although he had already formed a new Heretic Demon Hunter Squad of... and closes on According to the last census of the Old Alliance from a few years....
Chapter 279, ", System Crash", is the clearest early answer because it turns Irong Fetches's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Although they had only taken down three bunkers for the moment, Anat... and follows through with A grave challenge had finally arrived..
Chapter 342, ", Four Years", is the clearest early answer because it turns Void Shield's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Under this number, only 20% of the troops in the Rage Bear Legion... and follows through with This matter was thus dragged on, right up to now, for a whole year..
Chapter 332, ", Titan is Completely Done", is the clearest early answer because it turns Alliance's situation into a concrete plot event. The chapter turns that into something concrete by moving from However, the increasingly torrential heavy artillery and fierce... to Moreover, even if they could hold the line, who could come as....
Chapter 320, "A Larger Scale Raid", is the clearest early answer because it turns Windfalcons's situation into a concrete plot event. Early on, The interstellar warriors' ability to carry heavy loads was.... By the end, After the Windfalcons went back, they would load up another batch of....
Chapter 199, ", Battle Group New Blood", is the clearest early answer because the buildup finally cashes out in a real clash. Early on, But even so, these nine least capable boys should still stand out in.... By the end, Anatole didn't want to think about those things anymore.. Inside the broader family politics storyline, the danger stops being abstract and the conflict around the main cast becomes immediate, forcing the surrounding cast to react under pressure.
Chapter 239, ", The Essence of the True Realm", is the clearest early answer because Primal Fury Owl finally turns buildup into a real advancement. A useful checkpoint is the way the scene starts with [The upgrade project for the unique sequence has been unlocked and... and follows through with There'll be more by noon tomorrow..