Reading "Lord Randal" the intelligent reader may expect the poem to be about something regarding the Middle Ages: the word "lord", indeed, refares to the Middle Ages. 

Furthermore, the intelligent reader can see in the last stanzas the way Lord Randal distributes his possesions when he is near to his death: he leaves his brother all his houses and lands (the most of his possensions), his sister all his gold and silver (to be attractive for men) and anything to his mother. From this I can understand that, in the Middle Ages, brothers and sisteres were probably more important than parents.