Part of this depends on the breeder you got her from. Does your breeder have any requirements? Some breeders require that you use their kennel name. Some breeders require that all pups in a litter are named to a theme or that their registered name starts with a certain letter.

If you don't have any of those requirements, then you can name the dog anything you want. You can name her Princess Consuela Bananahammock and call her Maya if that is what you want to do. The registered name can, but doesn't have to have anything to do with the "call" name.