Bill, were you a self taught photographer or did you assist many photographers and get experience with a wide array of subject matter, film types, situations, and all of the issues of working on assignment? I know you assisted and had a commercial background, that's how we first met. From what I got from Dorothy's web site is that she's self taught and hasn't done much in the way of advertising or editorial assignment work. Sometimes it's better to back out of a project that you are not suited for and show potential clients that you are honest in your assessment of your abilities and not willing to take on a job at their expense that you may fail at. I think she has a far better chance of working with that agency in the future, because she was straight with them. They may come back at a later date with a job that mirrors what she actually does. If she takes on a job beyond her experience and blows it, she's poisoned her name with that agency, and as word tends to spread fast among the ad industry, with other agencies as well.
But you know Bill I may be the wrong person to ask about this situation as at age 44 I retired from advertising photography, closed my studio, walked away from a business I spent 25 years creating and now only shoot my personal work. I still have close friendships with many of my former clients, however I have been unavailable for any commercial assignments for the last 4 years and I haven't shot any color film in that time.
She said Prominent ad agency and national magazine, that doesn't sound like the Pennysaver to me and I got plenty of assignment work whilst still unknown, then again my portfolio reflected a certain level of experience and I got assignments that matched my portfolio.
I agree with you when you say you have to start somewhere. But the vast majority of people have done a certain amount of assisting of photographers on assignments before they took on advertising or editorial assignments. You know there is huge difference between working on assignment and just going out and shooting, there's a huge difference in pressure and consequence.