My family were a bit prone to exaggeration, and it was slightly odd! Especially as a teen, I used to just think 'oh god there's mum going on' and feel very ugly. It doesn't insulate you against insecurity about your looks at all, although I take the point at least you feel you have one person on your side in life.
I think the point I was trying to make was that saying your children are beautiful a lot or going on about looks I do think just reinforces the idea that looks are very important.
In the past, people didn't go on about looks as much in their children, it was considered a matter of luck and if you read Jane Austen there was often a 'prettier' sister and everyone just accepted their own looks may not be all that. More important qualities in a wife would to be a hard-worker if you were lower down the scale, and wealthy and well-connected higher up. In that value system, looks were an added extra but not the main event.
We now gush over our children's looks, but to what effect- if you look at rates of psychological distress, self-harm, teenage angst particularly amongst young women, they are higher than ever. I'm not saying it's causal, more that in a world obsessed by looks, it's easy to fall into that yourself and not provide any counter-messages to this.
And- people say, well I tell my dd's they are clever, brilliant etc. but all the research shows that girl babies are praised for looks and boy babies for strength and doing things.