Your sister could have been influenced by the media or the toys she had. For example, if she had a lot of baby doll - like toys that were girls, she might have wanted to recreate that with you. Also, in some families, there's a sense of playfulness and lack of strict gender norms, so she felt comfortable enough to dress you as a girl baby. It could also be that she just thought it would be a great photo opportunity to show her friends how she could transform you into a girl - like baby.
She might have been bored and looking for some entertainment. Dressing you up in different ways could be her form of amusement.
Perhaps she always wanted a baby sister and by dressing you as a girl, she could briefly fulfill that wish. It could also be that she was exploring ideas about gender and clothing, just out of curiosity. She saw you as someone she could experiment with in a harmless way. Another reason could be that she had some old girl baby clothes that she thought were too cute to not use, and you were the available model.
One reason could be for fun. Sisters often like to play around and dressing someone as a baby girl can be a form of humorous play. Another reason might be for a creative project, like making a home video or a photo shoot. Or perhaps she misses having a baby sister and wants to recreate that feeling.
It could also be out of necessity. For example, if there are not enough bridesmaids available at the last moment. Maybe in a small - town wedding where there are only a few young girls and they need a certain number of people in the bridesmaid group, so a boy steps in. He might be a friend or a relative of the bride. He is then dressed up as a bridesmaid to complete the set - up.
In the story, the sister could be very creative. She perhaps used makeup to complete the look too. The sister might have been inspired by a movie or a story she read. For example, if she liked a fairy - tale princess story, she made her brother or other family member dress as a girl to reenact the story. This would not only be a form of entertainment but also a way to strengthen their bond as siblings.
There could be a story where the sister has always wanted a sister to play dress - up with. Since she doesn't have one, she decides to use her brother instead. She carefully selects one of her prettiest dresses, a pair of her shoes that might fit her brother, and some accessories. The brother protests a little at first but then realizes that it's just a form of fun and bonding with his sister. They end up taking pictures and creating memories that they will laugh about for years to come.
The sister might teach the one dressing as a girl some 'girl - like' behaviors, like walking gracefully or talking softly. It could be a chance for the person being dressed to experience a different perspective.
The girl in the cartoon might be sneezing because of pollen in the spring. Or maybe she was playing around and pretended to sneeze for fun. Another possibility is that it's a part of a story where a sneeze leads to some kind of adventure.
Maybe she just wanted to have some fun. Sisters can be quite mischievous sometimes and dressing you as a girl might seem like a hilarious idea to her.
A sister, Sarah, and her brother, Max, were at home during a long vacation. Sarah was bored and came up with the idea of dressing Max as a girl. She rummaged through her closet and found an old party dress. Max protested a bit but then let Sarah do her thing. She added some of her mother's old jewelry to the look. As she was finishing, their parents walked in and were initially shocked but then burst out laughing. They all ended up having a great time talking about how Max looked like a proper little girl for a while.
I'm not sure if there are specifically 'famous' stories in the mainstream sense. However, in some family - based novels or memoirs, there might be such anecdotes. For example, in some old - fashioned family chronicles where siblings engage in all kinds of imaginative play, this could be one of the scenarios. But it's not as common as other themes in well - known literature.