A plot could involve Peter Parker accidentally ending up in Helen Parr's universe. At first, Helen is suspicious of this strange new hero. But as they start to share their experiences as superheroes, they find common ground. Maybe there's a villain who is a threat to both their worlds, and they have to team up to stop it. Along the way, a romantic relationship might start to develop between them. They could also learn from each other's family dynamics. Peter could show Helen a more carefree side of being a hero, while Helen could teach Peter about the importance of family in heroics.
Perhaps the plot could be set in a world where all superheroes are being hunted. Peter Parker and Helen Parr cross paths while on the run. They decide to form an alliance to protect themselves and their loved ones. As they hide out together, they start to discover more about each other. Helen might be intrigued by Peter's scientific mind and his web - slinging abilities. Peter could be in awe of Helen's elasticity and her ability to take on different forms. Their relationship could grow from friendship to something more as they face various challenges together, like outsmarting the hunters and finding a way to restore peace for superheroes.
One possible plot could be that they meet during a city - wide emergency. They initially clash due to their different ways of handling things, but then realize they can work together well. As they spend more time together, they start to respect and like each other.
There might be some out there. You could start by looking on popular fanfiction websites like Archive of Our Own or FanFiction.net. Sometimes these crossovers can be really creative, imagining how the characters from different universes interact.
One possibility is that their combined powers would make them an unbeatable team in the fanfiction world. Peter's spider - abilities and Helen's elasticity and super - strength could lead to amazing adventures. They might face villains who are threats to both their cities, and together they'd come up with creative ways to defeat them. Their relationship could also bring out new sides of their characters, like Peter becoming more family - oriented because of Helen's family - centric nature, and Helen becoming more carefree with Peter's youthful energy.
Peter's spider - sense could give them an early warning system. So when danger approaches, he could alert Helen and they could both be ready to act. Helen's ability to stretch and shape - shift could be useful for getting into tight spaces that Peter might not be able to reach with his webs. Together, they'd be a very adaptable team in any situation.
In this fanfiction, their marriage could be a result of a long - term partnership in the field of journalism. Maybe they both work for the same newspaper. Peter uses his superhero experiences to get exclusive stories, and Helen is an ace reporter in her own right. They get married and combine their skills to expose the dark underbelly of the city. Their relationship is filled with mutual respect and admiration. They have to deal with the challenges of a competitive newsroom as well as Peter's secret identity, which adds an exciting layer of drama to their married life.
One possible plot twist could be that their secret identities are at risk of being exposed just as they are about to get married. Maybe some villain discovers their relationship and plans to use it against them. For example, the villain could threaten to reveal their identities to the public or their families if they don't abandon their wedding plans.
Perhaps Helen discovers she's pregnant at a very inconvenient time, like when Peter is in the middle of a big battle or facing a major threat to the city. This could lead to a lot of internal conflict for both of them. Peter might feel guilty for not being able to be there as much as he wants, and Helen could be scared about raising a child in a world full of danger. Another plotline could be them preparing for the baby's arrival, which includes Peter trying to find a more stable life and job so he can support his family better, all while still keeping his identity as Spider - Man a secret.
One possible plot could be that Peter is on a school trip to Wakanda. There he meets Shuri, and they start sharing their knowledge about technology. They then discover a common threat to both New York and Wakanda and team up to stop it.
Their relationship could develop through shared interests. If they both have a love for helping the community, they would bond over that. They might start by volunteering together, which would lead to deeper conversations and eventually love. After getting married, they would continue to grow together, learning from each other's strengths and weaknesses.
A common theme is the power dynamic. Since Helen Parr is a superhero, there's often exploration of how that affects her relationship with the reader. Another theme is secrecy, as she has to keep her identity a secret in the original story.
I'm not sure about specific 'Peter Parker x Helen' fanfictions where Helen is pregnant. You could try searching on popular fanfiction websites like Archive of Our Own or FanFiction.net. These platforms have a vast collection of fanfictions, and you might be able to find what you're looking for by using the relevant search terms.