This sounds very strange to me. wisdom teeth and fillings are things they usually think about before starting the process and taking the impressions. Sounds like she could have made a mistake. Or maybe your trays really haven't been made yet. I think the only thing you can do is ask her directly why it's so urgent to do it now. And if she keeps insisting but you don't believe her reasons, then I guess you could always just say that you can't afford it (especially if it's the truth) but you'll think about it for next year... she can't argue with that, right?