The breeder I got my last girl from advertises on puppyfind, as do quite a few on YT. Since you'll be going to her home I think you're pretty safe. I love her floppy ears(Carmen Electra has a floppy eared tiny yorkie that I adore named Daisy). Also, yes, housebreaking in the winter in Michigan DOES suck but I'm doing it. You just go out, get the job done and bundle up your baby and hurry in.
It sounds like the lady has been very honest with you, it's a very reasonable price and she's tiny. Exactly what you're looking for.