Any breeder you talk to, call back, there may be issues as to why a week has passed and she has not called you back. I know my computer just crashed for a week. Luckily for me, I had a back-up I could go to. However, many people do not. Or just call them. Maybe she's had the puppies and realized she didn't have enough. And, no, we don't have a lot of breeders on the west coast.
As to crossing the border, I have two from Robyn and had no issues either time. The first time, I did all the right things and had everything ready. All the vet papers, the shots up to date, the sales receipt and all info pertaining to the pup. I did claim Shadow and paid duty. Wasn't much though.
The second time, I got a little smarter. Even though I had everything ready, I just told them at the border that I went to pick up my dog. I didn't really lie, I did pick up my dog. They just waved me on my way. As long as you have your paperwork ready, there shouldn't be any issues. Call the Customs Importing for Animals and they will tell you what you need. They are easy to work with IMO. I also work at the border, in the customs building, for a trucking company. So, even though I don't work for customs, I see a lot of what goes on. Many animals cross the border with no issues. And no, I didn't cross my bridge when I retrieved my dogs, I crossed another one.