There's an 8 digit number associated with each ADR. If you have that, it would help. When you call into Disney Dining and go through the menu, they ask you for your room reservation number or your home phone number. When the CM picks up, that information is usually in front of them. They might be able to get the # right off the screen. I know that when I changed an ADR, she said she saw it in front of her. You can always have your TA cancel the original one when she gets back from vacation too.