aww poor Topaz! you are so smart to start with a checkup at the vet, that's exactly what I'd do too.
I can tell you though, that my own dog will NOT budge from the warm bed until after 6:30am, and that's only because I make him. if he had it his way he'd sleep in everyday until 8am. my guy isn't too fond of going out into the cold to do his business in the morning either, but I boot him right out and believe me, he comes back REAL fast, runs straight to his fleece blanket and curls up in a ball, then he acts very dramatic and actually shivers and whines. like "poor me, those horrible people made me get out of bed!"
if all is clear at the vet, perhaps topaz got spooked by something outside, perhaps your body language is off, perhaps she's being coddled a bit too much about not going out (currently, she's getting rewarded for protesting). when my dog protests things, I get my "business" attitude on…. very matter of fact about things. I snap his leash on, say LET'S GO, and just start going. you could always snap on Topaz's leash BEFORE you even go downstairs. start your hearty walk in the house, and continue right out the door. Don't let her rule the walk either, if she stops, keep on walking. you lead, she follows. if my dog stops to smell the roses, I give the command LET'S GO! and keep moving.
I do hope everything checks out ok at the vet though - keep us posted!