It depends on how well you know her. Seperating a girl from her usual flock is quite tricky without the experience. But I'd recommend you do so to enhance both your experience and confidence levels (as long as you can handle rejection). Your statement of "I don't feel comfortable asking her in the presence of a bunch of other folks" is the true beauty of it all. Get out of your comfort zone, stop getting nervous over such an easy thing as asking a girl to a dance, and bascially stop caring. If you stop caring about rejection and focus on improving yourself for the future (for 'getting' girls or even just being a better person), things like seperating a girl from her "click" would be alot easier, as well as life itself. "Fear of rejection is far worse than rejection itself". So go out there and just do it. If you don't exactly know "how", read the DJ bible, there's plenty of tips on "how" to do it, except for the fact that many of the "how's" are based on the writer's personal experiences, which would mean... it might not work for you, and if that happens, learn to "wing it" without fear, but with confidence... "Mind over Matter" for the most part..