I'm not sure if it was a difficult delivery
She went into the bathroom and had it in there and didn't even make any noise to wake us. I'm not sure how big Zoe normally is, but yesterday at the vet she was 8lbs so she's not small at all. She only had the one puppy and that puppy seemed pretty big. The father is smaller than Zoe, about 6lbs.
She is still moping around the house and I feel horrible for her.