I'm not sure about this specific story. It could be a very unique or made - up situation. Maybe the sister had some strange ideas and forced her brother to dress or act like a girl for some reason like a prank or as part of a family game.
It could also be that the sister is trying to prove a point about gender equality. By making her brother experience what it's like to be a girl, she wants to show that there are no big differences between the two genders. However, this is a rather extreme way to do it.
There was a boy, Ben, and his sister, Ava. Ava was obsessed with makeovers. One day, she had this wild idea to give Ben a girl - like appearance. She didn't really give Ben a choice as she pushed him onto a chair. She started with a foundation that was a bit too light for him, making him look a bit ghostly at first. But she continued, adding mascara to his lashes which made his eyes look huge. She put a headband with a big bow on his head and a pastel - colored dress. Ben felt really strange, but Ava was so proud of her 'creation' that she showed him off to their neighbors, who also had a good laugh about it.
Once upon a time, there was a boy named Tom. His sister, Lily, was really into fashion and makeup. One day, she decided that Tom needed a makeover. She forced him to put on a dress, wear makeup and a wig. Tom was reluctant at first, but then he found it kind of fun to see himself in a different way. In the end, they took some pictures and had a good laugh together.
Well, there's this boy, let's call him Jack. His sister was obsessed with makeovers. One time, she caught Jack just lazing around and declared that she would give him a girl makeover. She made him wear a dress from her closet, tied his hair up, and used all her makeup skills. Jack protested at first but when he saw how different he looked in the mirror, he couldn't help but laugh. His sister had successfully turned him into a 'girl' for the day.
Well, the story could start with the sister feeling left out because her brother always gets to do 'cool' boy things. So, as a form of revenge or just for her own amusement, she forces a makeover on him. She might raid her own closet for the girliest clothes she has. She could pick out a frilly pink dress and some high - heeled shoes. For the makeup, she might go all out with bright red lipstick and lots of eye shadow. The boy would be horrified at first, but as the makeover progresses, he might start to see the humor in it. And maybe in the end, they both learn something about each other and the differences between boys and girls.
The boy can also try to resist his sister's actions directly. He should firmly say 'no' when she tries to make him act like a baby girl. He can find his own interests and hobbies that are more in line with his true self, like if he likes sports, he can focus on that and show his sister and others that he has his own identity that is different from what she's trying to impose.
Since we don't have much information, it could be a story about a forced transformation from a boy to a girl in a fictional or even a metaphorical sense. For example, in some fantasy stories, a magic spell or a curse might force a boy to take on the physical or behavioral characteristics of a girl. It could also be a story that explores themes of gender roles and the power dynamics when someone is forced to step out of their own gender - associated norms.