It could also be that she saw certain qualities in you that she associated with girls. Maybe you were more sensitive or artistic, and she wanted to encourage those traits by making you more 'girl - like'. She might have believed that by doing so, you would be more true to yourself in her eyes. However, this approach might be controversial as it could be seen as forcing a gender identity.
Well, it could be that your mom made you dress like a girl. Maybe she always wanted a daughter and would sometimes put you in girl's clothes, do your hair in a girly way. For example, she might have put you in a frilly dress and bows for special occasions.
One reason could be for a bet. Maybe mom made a bet with someone and as part of it, she had to make me dress as a girl.
She might have been influenced by the idea of gender - bending play. It's fun for some kids to explore the opposite gender's activities. So she thought it would be cool to make you be a girl for a while. She could also have been inspired by movies or stories where characters change genders for a short time, and she wanted to recreate that in her own way with you.
One reason could be that the sister has some sort of enchanted object. For instance, a mirror that has the power to change one's appearance and gender when looked into. So, when the boy looks into it by accident or at his sister's urging, he becomes a girl.
It might be due to a medical condition. For example, if the girl had a urinary tract infection that made it difficult for her to control her bladder, the mom would put her in diapers to manage the situation until she got better.
Perhaps she was influenced by her own upbringing. If she had a great relationship with her mother when she was a little girl, she might be trying to replicate that with you. She could also be doing it as a form of protection. By making you into a 'baby girl', she might feel like she can shield you from the harshness of the outside world in a more motherly way.
One possible motive could be her sense of humor. She might have found it hilarious to see you in girl's clothes. Another reason could be that she was reminiscing about her own childhood or the idea of having a daughter. So, she just wanted to experience that through dressing you up.
One reason could be regression. For instance, if the child faced a big change like starting daycare or a new sibling arriving. This stress could make them forget their potty - training skills.
It might be due to the mom's own unfulfilled dreams. Maybe she always wanted a daughter and in a way, she tries to live out that dream through her son. She might dress him up as a girl, involve him in girl - centric activities like ballet or doll - playing, hoping to create a kind of surrogate daughter - like experience.
She might have been influenced by some old family traditions. In some families, they like to do cross - dressing for certain events as a form of entertainment or to create a unique family memory. Another reason could be that she wanted to show me that clothes don't really define gender. By dressing me as a girl, she was teaching me to be more open - minded about different ways of dressing.