Isabella
I'm probably gonna get lots of bad feedback for this... but I FUCKING hated Isabella. Like, I know the movie focuses on Abuela's treatment of her family (Mirabel included), but are we forgetting the fact that Isabella treated Mirabel EVEN WORSE? Like, she's been hitting her with flowers any chance she gets and not to mention that she complained about the pressure of being perfect for her family. The moment she said those words to Mirabel, I was like, "YOU'RE A SIBLING! FUCKING ACT LIKE ONE!"
On my post of Disney's Coco, I explained that I didn't like Abuelita Elena for hurting Miguel's feelings after breaking his guitar and called her toxic, but at the end of the day, it made sense within the context of that film since it started Miguel's journey to the World of the Dead where he would prove that music can be special if given to your family. Also, in the end of that movie, when Miguel sings the last reprisal of Remember Me to Mama Coco, she was moved to tears and that was when she decided to stop going overboard with the No Music rule.
In this movie, Isabella's behavior, aside from her complaints about being perfect, made no fucking sense within the context of what the movie established with the magic candle's connection to the house. Maybe the character could've been stronger had she understood Mirabel's motivations on wanting to fix the house and help confront Abuela. But nope, the producers/writers just decided to go with the "aloof bitch" route. Plus, the character herself had no remorse for her treatment towards Mirabel which pissed me off. Then again, I've seen other movies where certain female characters in animation have been WAY more toxic (looking at you, Sisu).