Aw, I get it, I really do. Having a very attractive child is something you become conscious of. They draw attention. People stare. You do start to worry they might get abducted etc.
I honestly did worry when dd2 was little. She was very appealing looking, and even my mum said that she worried about her attracting the wrong sort of attention "with her being so beautiful".
As she has grown up, she has become very self-conscious unfortunately, which I think is partly the additional "noticeability". From a young age, people have commented and little boys have stared open-mouthed at her. She feels watched and instead of relishing it, she has ended up feeling awkward about it.
She goes to a girls school, which I'm grateful for. And fortunately as she has got older, acne, greasy hair and general teenage gawkiness have taken the shine off her a bit. She's still beautiful but not as strikingly, shinily perfect as she was as a kid.
And that will happen to your daughter too, so it will be an advantage if she doesn't base all her self esteem on her looks - that's a tough call while being a teenager as they are all self conscious if not paranoid!
As for the future, there is a great levelling effect of clothes and make-up. Other girls will catch up such that there isn't such a big differential. It will be lovely for her, but she'll have more control over how much to play up/down her looks which she may well do to be taken seriously academically (I know!)
I just wanted to say ignore the comments on here. Your post came across as modest and humble to me. I'm not some parent blinded by love to reality, and I'm sure you aren't either.
I'm afraid I have made the mistake of telling her she is beautiful. I've done this to try to boost her very low confidence, but I know it's classically not what you're supposed to say. I have started to talk up other qualities.
Apart from that, just enjoy it! Your kids being exceptional in some way is lovely, celebrate it.