Dad suspects that his daughter's good looking teacher might not be as popular as everyone thinks. When asked why, he responds:
Dad:「とかく美人はなんやかんや言われるからなァ」
Because various things are said about beautiful women
Mum:「そうね。美人ってだけで生意気だなんて言われたりね」
That's right. It's said that only beautiful women are cheeky.
Dad then seems to get angry and asks mum how she would know such a thing.
I think my translation of mum's sentence must be wrong. I'm not understanding the 美人ってだけで part. At first I assumed this was equivalent to 美人はだけで. But I think if you use は and だけ together then it must be だけは and not はだけ, so I guess the same is true with って?
Irrespective of that I don't see how translating だけ as 'only' makes any sense here. Nor, why dad would get angry at the comment.