That would be a good idea Almightyra, but most people don't think of food as a means of making money. Also you gotta find a buyer, find a way to preserve it until you can sell it...maybe other red tape. So like anything there would be obstacles. Basically any way to use the duplication ability for money would involve them investing time/money in a talent that is likely to be gone tomorrow. Still if she could pick her additional power this would be a viable way of getting some legit side income.
Of course I think what would be easier for Gail to think of and implement would be using it to duplicate illicit materials. She already has contacts for that, the knowledge of how to do it and could get something to start her out fairly easily.