@foussi Would you mind posting pics of the parents and their kids? It is true that teens can look a little on the awkward-side with mouths that are too low and features that don't quite fit their faces but this doesn't mean that good looking teens are not possible.
As @Idontrcall says, pretty girls don't always make handsome sons and handsome boys don't always make pretty daughters. Things can also go wrong when kids are blends of their parents and the parents have features that don't mesh well with their partner.