One possible fanfiction could be about Natasha's sister joining the Avengers. Maybe she has some unique powers like the ability to control minds on a small scale. She could start as a bit of an outcast, but as the story progresses, she earns the respect of the team through her courage in battles.
One possible fanfiction could be about Natasha's sister having some sort of superpower that makes her seem 'crazy' to the outside world. For example, she might have the ability to see alternate dimensions and her ramblings about those other worlds are misconstrued as insanity. In the story, the Avengers could initially be wary of her but then come to realize her power is actually quite useful.
The plot could revolve around Natasha's sister being a secret weapon. She might have been locked away for years because of her uncontrollable powers. When she is finally set free, she has a hard time adjusting to the normal world. The Avengers, led by Natasha, try to train her and help her control her powers. Along the way, they face many challenges, like villains who want to capture her sister for their own gain.
She could be a super - spy too, but on a different side initially. Maybe she was brainwashed by a shadowy organization. Natasha then has to fight her sister while also trying to bring her back to her senses. It would be a story full of action and emotional turmoil.
One great 'Avengers Steve and Natasha fanfiction' is 'The Red and the Blue'. It beautifully explores their relationship in the context of their Avengers duties. The author does a wonderful job of showing their mutual respect and the unspoken connection between them.
In a fanfiction scenario, Natasha and Steve's relationship could develop in a way that leads to her pregnancy. Maybe it starts with a deep emotional connection during a difficult mission. As Natasha goes through the pregnancy, she struggles with her identity as a former assassin becoming a mother. Steve, on the other hand, draws from his own values of family and protection. The birth could be a moment of great joy and new beginnings for them, symbolizing a new chapter in their lives not just as individuals but also as a couple within the Avengers family.
To develop kid Natasha, you could focus on her backstory. Maybe she was an orphan and had to learn to fend for herself at a young age. This would make her resourceful and street - smart.
First, they would need to figure out if it was a trap. But assuming it's not, they could divide into teams. One team, like Ant - Man and Wasp, could infiltrate the place in a stealthy way. Meanwhile, Doctor Strange could use his magic to create illusions and misdirect the captors. The Avengers would have to work together, combining their different powers and strategies to rescue Natasha successfully.
In many of these fanfictions, Natasha's character is explored through her vulnerability when she's sick. For example, in some stories, we see her usual tough exterior crack, revealing her fear and dependence on her team mates, which is a side of her we don't often see in the movies.