i'' so sorry about your baby. Losing our babies is devastating and even moreso when you don't know what happened. Same thing happened to a bully of mine. He was fine, I said hi to him, he ate breakfast and watched me pile laundry into the dryer. I returned after 15-20 minutes to check the dryer and he looked sound asleep but his ears weren't twitching from the noise I was making. I immediately ran ocer to gim but he was gone. It was devastating and I still do not know what happened. I held him and screamed for what seemed like hours but was only around 20 minutes. It was awful and i'll never forget.
You may never know what happened but she was loved until the end and that's what matters most. As others have suggested, I'd have her cremated. I'm sorry and I am sending comforting thoughts
My baby is very sick (under a vets care) and this is my biggest fear.