That's hilarious. I love hearing first reactions.Willow's become an ubiquitous name now - though I don't think most of them are actually named after the character. The first person I knew called Willow would be about 18 now - and I suspect she and the first generation of Willow's were, but then it just got picked up and used by parents who just thought it was pretty. Hermione is similar - when HP was first published it was so unknown that most people didn't even know how to pronounce it, but now no one would bat an eye on meeting an Hermione - but they won't be specifically named after Miss Granger.
It's funny - I remember before I started watching Buffy my friend who did watch it saying that Buffy's best friend's name was Willow and me being very scathing about it: "Buffy's best friend is called Willow? Oh for goodness sake what are the chances? Does nobody have a normal name? What a ridiculous show. What's the boy called? Xander? well - I never did."
But now Willow is the 19th most popular girl's name in England and Wales, and more and more boys called Alexander shorten it to Xander not Alex.