Her power could be related to telekinesis. This would be a cool addition to the story as she could move objects around without touching them. In a fight, she could disarm opponents by simply using her mind to throw their weapons away. And she could also use it in more creative ways, like building things by moving the parts into place without using her hands.
She could have super - intelligence like her father. This would allow her to understand complex technology and science with ease. She might be able to invent things on the fly, just like Tony did with his Iron Man suits. For example, she could create a device to disable an enemy's weapon system during a battle.
Maybe she has the power of energy manipulation. Since Tony worked a lot with different forms of energy in his suits, it would make sense for his daughter to have some connection to energy. She could use this power to create force fields, or to power up other superheroes' abilities in a fight.
Maybe he doesn't fully understand his powers yet. Tony Stark is a scientific genius, but new powers might be beyond his current understanding. He could be worried that if he reveals them too soon, he won't be able to control them properly and might cause harm. So, he chooses to hide them while he studies and figures them out.
Pepper Potts. She is very close to Tony and knows him well. She might notice some strange behavior or small signs that lead her to suspect he has hidden powers. For example, he might unconsciously use his powers in a moment of stress or danger when he thinks no one is looking.
She might start by integrating some of Stark's technology into her Ladybug powers. For instance, her yo - yo could have new functions like advanced tracking or energy projection, inspired by Stark tech.
In fanfiction, Tony Stark might have enhanced intelligence powers. He could solve complex problems at a super - fast speed, like coming up with new energy sources in minutes. His suit could also have new abilities, like teleportation. For example, he could zap himself from one side of the planet to the other to stop a disaster.
She would definitely have engineering skills. Just like Tony, she could build amazing machines and gadgets. Maybe she'd create a device that can instantly transform any fabric into a bulletproof material for her fashion - related projects. Also, she'd probably be a quick learner when it comes to technology, able to hack into systems if needed.
Buffy might inherit Tony's engineering skills. So she could be able to design and build her own high - tech weapons or armor. Additionally, she could also get his strategic thinking ability, which would be very useful in battles or when facing difficult situations.
Another idea for this fanfiction could be that Tony Stark's daughter starts as a sort of 'Avengers - in - training'. She is constantly trying to prove herself to the established members. There could be a lot of action - packed scenes where she is in dangerous situations but manages to use her wits and any skills she has learned from her father to get out of them.
Love and friendship are also common themes. Her relationships with friends at school or in the superhero community, and her romantic interests if any, are often explored. It gives a more well - rounded view of her character as not just a Stark, but also a young girl growing up in a complex world.
One popular type of fanfiction could be about Tony Stark's daughter joining the Avengers. Maybe she inherits his genius and creates her own high - tech suit. She might struggle at first to be accepted by the existing Avengers, like Iron Man did. But through her skills and determination, she gradually wins them over and becomes an important part of the team.
Pepper Potts could be a common character. She might be in a position where she tries to mediate between Tony and his unwanted daughter, either trying to get Tony to be more accepting or helping the daughter understand Tony's perspective.