Other children also know what is expected of them in public. But according to your mother it is quite alright for mother, with children who know what is expected of them in public, to be left alone while she goes into another room to try on clothing.
But, even though your mother finds that acceptable, she finds it unacceptable to be 5 feet away from a child. A child she has no clue whether had been taught what was acceptable in public.
I can't wrap my brain around your mother's logic.
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