The tuning above (DGDGBD) is sometimes called "Spanish " tuning and is very much like 5string BAnjo's G tuning .. using a banjo chord tutor will be very enlightening for getting started. It sounds like Kate is using more open additions like G sus 2's and G sus 4's and her querky sence of rythum really is wonderful .She is one of my faverite guitar players besides that angelic voice ! All the best , Guy