One possible reason could be psychological. As she grows up, she might start to imitate her mother unconsciously. For example, she may adopt her mother's mannerisms, like the way her mother talks or gestures. Another reason could be environmental. If she is constantly surrounded by her mother's influence, such as living in the same house with all her mother's things around, she may gradually transform in some ways. Maybe she starts to take on her mother's role in the family, like taking care of younger siblings just as her mother did.
One possible reason could be the mother's own unfulfilled dreams of having a daughter. Maybe she always wanted a girl and in an extreme way, she tries to transform her son into what she envisioned a girl to be.
Maybe she broke her mother's favorite vase while playing. It was an accident but she knew it was important to her mother.
In a story, a girl might need to apologize to her mother if she failed to keep a commitment. For instance, if she promised to help with the household chores but didn't do it. Or she could have disobeyed her mother's instructions, such as not coming home on time. Also, if she gossiped about her mother to others, that would be a reason to say sorry.
In a story, a girl might apologize to her mother if she failed to keep a promise. Say, she promised to study hard for an exam but instead she went out with friends and got a bad grade. Or, she could have borrowed money from her mother and spent it on something frivolous instead of what she said she would use it for. Additionally, if she had been rude to her mother's friends or guests, she would surely need to apologize.
One reason could be for fun. Maybe the mother just wanted to have a laugh and see how cute her son would look in girl's clothes. For example, during a family photo shoot or a special family event like a themed party at home.
It could also be to teach the son about empathy. By experiencing what it's like to be dressed as a girl, he might gain a better understanding of how girls might feel in certain situations. For instance, how they are treated differently in terms of clothing expectations.
It could be that she misses having a daughter. So, dressing her son as a girl gives her a chance to experience some of the things she might have done if she had a girl, like dressing up in cute girlish outfits.
Another possibility is a curse from the supernatural world. Maybe he entered a haunted place or broke an ancient taboo, and as a result, a curse was placed on him to transform into a dog as a form of penance or to teach him a lesson about respecting the unknown.
It could be due to a lack of proper boy - themed clothing at a particular moment. For instance, if they are in a hurry to attend an event and all the boy clothes are dirty or not suitable. So, the mother decides to dress her son as a girl as it's the quickest option available. Another reason might be to teach the boy about gender fluidity and acceptance from an early age. By dressing him as a girl, she can show him that it's okay to explore different looks and identities.
One possible reason could be for fun. Maybe she just wants to see how cute her son would look in girl's clothes for a laugh or a unique photo. Another reason might be that she doesn't have a strong sense of gender - specific clothing. She might think that clothes are just clothes and doesn't see a big problem in dressing her son in girl - like outfits.