For kids who know they must eventually grow up but aren't sure they want to take on the responsibilities of adulthood, Sarah is a very relatable character. However, grown-ups are more likely to feel that her petulance, lack of consideration for others, and multiple pronunciations of "it's not fair" make her pretty insufferable. Sure, she has some good qualities, including intelligence, grit, and determination, but her immaturity makes it hard to really like her – especially early in the film.
It's possible if Sarah was younger, it would be easier to forgive her youthful peevishness, but at 16, Sarah seems a bit old to feel so put-upon. After all, this is a character who gets mad at her baby brother for taking her teddy bear and whose room is full of toys and children's books. This may all be good fuel for Sarah's clearly active imagination, but it seems odd that she hasn't moved on to more grown-up fare — after all, high school is when many fantasy-loving kids tackle the "Lord of the Rings" novels. Of course, today, 16-year-olds in pop culture tend to act like adults, which is often disconcerting too. It's not that adults would find Sarah more likable if she acted like one of them, but she would be easier to appreciate if she was starting to take on the responsibilities of a teenager, which should reasonably include looking after her baby brother.
