Thanks for all of your thoughts and comments. I really appreciate them.
As for "Trace," the 13-mo-old puppy who died under the blankets, I wonder how much he weighed or how much that might have to do with it....
On our bed we have lots of separate covers, not just a thick comforter or two. I myself get entangled in them sometimes and that's aggravating to me. For a little pup to want/need air and not be able to find its way out or to get entangled, well I don't like that idea.
I'm going to try wrapping Jewels up in a blanket that fits her and see if she's happy with that.
Oh, the ongoing questions that come with being a first-time yorkie mom! I'd be lost if I couldn't find such great answers from you all who have more experience.