Hi Its a minefield. Each type of mic has its own limitations and applications and each person has preferences and dislikes. Mics can cost a few bucks or a few thousand bucks so it might help if we know exactly how much she wants to spend and the exact purpose and application the mic will be used for. I take it that it is a live performance? How is it being recorded? Is she using any amplification? What external noises are we talking about? Does she want the orchestra recorded seperately or on the same mic? It would be very difficult to have one mic that will record clearly all the orchestra plus her vocals but will eliminate any other external noise. More info please.