If she is inexperienced, she'll probably have no opinion on them, or be a little afraid of them, lol. (Sort of a 'fear of the unknown'.) But she shouldn't be turned off by 'em because every man has a pair, that's just the way it is.
Honestly, the genitals in general aren't the most attractive parts humans have, but they're essential and can be a lot of fun, and hopefully any girl you meet will appreciate their purpose. Don't worry about it.