Maybe it is me.
1) She could be dumb as rocks, but if this is true how does our judging her help this world?
2) I have worked retail for many of years before, and the stress, the distractions, being overwhelmed doing 6 things at once but also being broke during that period. Well during those times my brain did not always think in the most "open-ended" problem solving / creative thinking mindset. You can get tunnel vision, solving the problem instantly, even if it's not the best way to solve the problem for your mind is distracted and going to the next step, or solving the next thing. Shrug I can get As on Calc 2 and be dumb as rocks on the most efficient way to make change.
I tried to change the subject for I felt your post was kind of judgey. Maybe she is dumb as rocks, maybe it could be a dozen other things. You don't know so why worry / complain?
-----
I would have asked if you were having a bad day then, but you made it sound enchanting when you took some time off in the sun and water, visiting family.