Thank you, everyone. Today two small things happened. My husband and I were in different rooms and I heard a cat cry just once the way Prudence cried when I put her in the box to go to the vet yesterday. She never really cried at all most of her life, but in the box she kept protesting and sounded like a kitten. I heard the cry but thought that can't be since we put her to sleep yesterday. Later I mentioned that I was hearing sounds as if she were still here and my husband mentioned that he heard one cat cry like the way Prudence sounded yesterday. So we heard the same cry. We live in an apartment building but Prudence was the only cat we ever saw or heard in the building.
The other thing was that I walked into a card store today. I am researching how to sell my art for commercial use like cards, mugs, etc. And I felt something give me a big nudge on the leg. It was a beautiful tabby cat and he wanted to be petted. There were other people in the store but he bumped me and stayed as if he had a message. I hope.