Guts

Best part about Joshua Tree was the rocks all around that the girls could explore.  As seen here, it took Lucy and Caroline working together to get each other over a gap.  At the same time, Ellie was climbing her own rock behind me, with similar success.  Yes, they can be typical siblings with each other, but I'll take several more adventures like this where they showed serious courage.  (Not videoed was Ellie later clearing the same gap just because her sisters believed she could and she listened.)