Yes, she does! My Sheppard Beagle Sugar smiles at me all of the time. She got that from her mother Spunky. When Spunky was alive she smiled like no other beagle that I have ever seen, especially after she had been for her walk. When the two of them were together and playing out in the yard, they both had big smiles on their faces.
Puppies smile too. Spunky had three litters and I can remember how happy they looked while running out in our yard or in one of the fields on the farm. It was so funny watching them wrestle with each other and ending up in one big scrum. One of the reasons why I had to have Spunky spayed was, because I would become more and more attached to each litter and it became harder to give them away.
I pet sit from time to time. One of the homes has brother and sister Pugs and they smile a lot. The owners say that I spoil them while they are away and I deny it, but we do enjoy each others company. They like to challenge my authority from time to time and I always know it from the silly grins on their faces.