Did this gallery sell photography? They might have no experience in it, and therefore have a bias against digital work. Galleries are simply retail stores for art. Each gallery owner (or, shop keeper) sets up the wares that they want to sell, think will sell, etc. You have to make sure that any gallery you approach actually sells the type of work you do. Look for a place that sells work that you'd like to have as company, and approach them.
Also, I'd recommend approaching them yourself. From my understanding, many gallery owners dislike going through a middleman, and this could have swayed her response.
Dan