As infinitesunrise pointed out, it's been ages since I've seen the movie, but I don't remember her being sexualized from the perspective of the audience, only the literal pig sexualizing her, and then growing as a person.
We live in a society which sexualizes teenage women, a work including teenage women being sexualized doesn't make the work itself problematic if it's in a negative or simply realistic context.
I could be wrong, it's been ages since I saw it and there's been a lot of really bad things in older media I just kinda memory-holed.