More specifically it's a Guild M85 as seen HERE ... Kinda like a Gibson LP bass they have solid mahagony bodies
I keep debating about getting a Waterstone Bass...the Guild looks very similar. I tried an Ibanez Artcore and wasn't impressed with it at all. http://www.waterstoneguitars.com/new_guitars/IndraBass.jpg
Yes, Sheryl is a small woman. She bought one of my Scroll Basses back in 2002. Last I knew, she still has it at home in her studio. I heard that she enjoys playing it in the studio, but won't take it out on stage. It's physically too big for her and looks silly. It's 35" scale, 48" long. I think she's around 5'1".