Stevie is a first time mother, and this is the first sighting of her joey, snoozing half out of the pouch. Video for perspective: https://youtu.be/aG03tPfinlg Thank you for such lovely comments and thoughtful questions and being here with me.
@fbailey twins have been documented but are pretty rare. There are two teats in the pouch, but they are quite close together. Once I saw a mum with twins on her back. I think it would be a huge burden for mum, and the pouch stretching, no no no I can't imagine :)