They have been good friends since the day we brought Nala in from outside. Every single day while I'm doing my homework Marley lays by my feet, and Nala always ends up coming over to have snuggle time with her. It's so cute, and I always take a break to watch them. You'll even see Marley cleaning Nala at one point, and Nala does the same to Marley in the second video (click the link below the first video).
The second video can be seen here. In this video you will see Marley try to share her baby (the stuffed animal) with Nala, and you'll also see Nala cleaning Marley. These two are so stinkin' cute!