I think it's very sweet. :) I've only known one
Claire - a girl in my class in like first grade. I think she was a year older than me (I had a first/second split class). I'm really surprised at the popularity. I never hear it.
I prefer the
Claire spelling because
Clair and
Clare are masculine IMO. (My friend's dad's name is
Clare.)
For some reason, I thought of
Claire Margot. I'm not even a huge
Margot fan, but I like them together.