Yes, Daffy, of course animals have souls. I love your idea of putting part of your cremated Moxie into a necklace when she dies, keeping her close to you. The following link expresses beautifully what will happen to her after she 'dies'.
I've sent this link to a couple other related questions, such as do animals go to heaven when they die, and what do you say to someone who has lost a beloved pet.
This piece addresses all these questions and I want to share the beauty, comfort, and encouragement it has to offer, whenever it is appropriate.