Has she ever been to the US before on such business, and has she ever been there since you have been residing together in the UK?
She has worked in the US before. (Prior to our relationship.) And she's been there for visits (visa waiver program) several times since we became involved. She's never mentioned our relationship to US Immigration--she has never been asked about it, and has no reason to volunteer the information.
The last time she entered, which was a few weeks ago--she was in Vancouver and made a day trip to Seattle to visit some friends, I was actually at home in Harrow--they gave her a bit of a hard time. Apparently they wanted to know WHY she was visiting the West Coast since she usually visits the East Coast, and were unsatisfied with her truthful answer that she was visiting her friends. They made her recite the exact dates of her last few trips in and out of the States, while they checked whatever was coming up on the screen. Poor thing has ADD and a bad memory, so this was very nerve-racking for her. I guess she got it right, because they let her through after a couple of minutes, but they were nasty about it.
What the hell do you do when you're standing there telling the truth and you're not believed?
Usually the work visas are arranged by the opera house/symphony and her agent , but since 9/11 the US has gotten VERY persnickety about O-1 visas for artists, and is basically using any excuse to not grant them. She hasn't had any work opportunities over there since we've been together, so it hasn't come up yet--I guess we'll cross that bridge when we come to it.