At the time when that ad ran, I remember thinking that character might be the actress Brooke Langton--but now, in retrospect, I think you are right: it was/is our 'Art Girl.'
I cannot find that Qwest ad left up on the Web anywhere, and I don't remember the name of the agency that did those spots (not that the agencies are necessarily a big help on this).
Anyone out there who worked on any of these ads, or who crossed paths with her at a casting session or acting class?