Like accioslash said, there's always the chance your giftee won't like your story, but on the other hand, there are plenty of people like me who won't mind at all if you've never officially written anything before.
I've loved every gift I've ever received in an exchange, precisely because it was a gift, and someone cared enough to write what I had asked for. Besides, even if it isn't quite up your recipients alley, someone out there will be happy you've written it! ♥