Why does Dr. Wendy say ‘water’ like that?

Dr. Wendy has an unusual way of speaking with certain words that’s hard to describe. I notice it most when she says ‘water’ but there are a couple other words too.

Is it an accent? Does she have a slight lisp? An old jaw injury? What?? She’s one of my favorite Potomac HWs but I can’t figure it out and it drives me crazy lol.