A plot could be that the teen girl has been training in a secret art form, like an ancient form of combat. When a man, perhaps a villain in the story, underestimates her because of her age and gender, she surprises him with her skills and overpowers him in a fight.
Maybe the teen girl is part of a special group that has enhanced abilities. She has the power of super speed. A man, who is an enemy of the group, challenges them. She races around him, confusing him, and then uses her speed to knock him off his feet and overpower him, showing that her youth and unique ability make her a force to be reckoned with.
One possible theme is empowerment. It shows that age and gender don't limit one's ability to be strong and capable. For example, a teen girl might overpower a man in a debate by having more well - reasoned arguments.
In a magical world story, a teen girl discovers she has special powers like telekinesis. A man, who is a bit of a brute, tries to force his will on others. The girl uses her telekinetic powers to stop him. She lifts him up in the air and makes him realize that he can't just push people around, especially not her.
One story could be in a magical world where a teen girl discovers she has latent magical powers that are far stronger than a powerful wizard who is a man. She uses her powers of light to overpower his dark magic.
Perhaps there's a genetic experiment that accidentally turns a straight male teen into a girl. His family has a hard time accepting the change at first. But as time passes, they see that he's still the same person on the inside. He then embarks on a journey to find a way to reverse the change while also learning a lot about himself and the concept of gender along the way.
One possible motive could be power play. The teen girl might be in a position where she feels powerless in other aspects of her life, so she exerts power over the old man in this extreme way. Another could be a form of rebellion against social norms. By making the old man crossdress, she is challenging the traditional gender roles that society has set.
The teen could face social ostracism. People would likely look down on her actions. The married man could face a damaged reputation and problems in his marriage, like his spouse losing trust in him.
A teen girl might overpower a man in a rescue situation. For instance, if a man is trapped under a relatively small but heavy object, a strong and determined teen girl could use her leverage and physical strength, combined with her courage, to lift the object and save the man. This shows that she has the power to overcome what might seem like an impossible task.
One possible plot could be that Anna discovers her fire powers during a dangerous situation, like when she's trapped in a burning building and suddenly realizes she can control the fire. Then she has to figure out where these powers came from.
One possible plot could be that as a girl, Bart gets involved in a girls - only club at school and has to deal with the typical girl - group politics.
One reason could be a change in diet. Maybe she started eating more junk foods like chips and sodas. Another reason might be a lack of physical activity. If she reduced the time she used to spend on sports or outdoor games, it could lead to weight gain. Also, hormonal changes during puberty can sometimes affect the body's metabolism and cause some weight increase.