It could also be due to long - hidden family tensions. Isabela might have bottled up her frustrations and unknowingly takes them out on Mirabel. For example, the pressure she has been under to always be proper and present a certain image in the family, and when Mirabel starts to question things, Isabela snaps.
Perhaps she tries to understand Abuela's perspective. Mirabel is a kind - hearted girl, and she may think that there is a reason behind Abuela's actions. So she might try to see things from Abuela's point of view while still feeling the pain of the punishment.
The 'boy cuts off own hand machete story' is quite horrifying. There could be multiple reasons behind it. It might be that the boy was in a dangerous environment where the machete was easily accessible. If he was living in a rural area where machetes are commonly used for farming or other tasks, and there was a lack of proper supervision. Also, it could be due to a moment of panic. Say he was being chased by an animal or in a fight and in a desperate attempt to free himself from something, he accidentally used the machete on his own hand. Or perhaps, as mentioned before, there could be underlying mental health problems that caused him to act in such a self - destructive way.
Mirabel might be initially shocked and heartbroken. She loves her family and the village, so being banished would be a huge blow. She could cry and try to plead with Abuela to change her mind.
She might be heartbroken at first. After all, being kicked out by her own abuela is a big blow. But then she could become determined to prove herself. So she might set out to find a way to show that she is an important part of the family even without a magical gift.
It could be her mother. Mothers are often the ones who enforce discipline in the family. Her mother might feel disappointed in Mirabel for lying and give her a punishment to teach her a lesson.
She might lose the trust of her family members. In the Encanto family, trust is crucial. If Mirabel lies and is found out, her family may start to question her honesty in the future.
Another reason could be that she wants to explore the world on her own terms. In the fanfiction, Mirabel may be tired of always being in the family's protective bubble. She desires to see what lies beyond the village and the mountains, so she runs away to start her own adventure.