Consider these elements of the two stories in The People Could Fly.
"The Beautiful Girl of the Moon Tower".
the father in the tower
"Manuel Had a Riddle"
Manuel's mother
How are these elements of the two tales similar?
Both the father and the mother serve as obstacles to the heroes' quests.
Both the father and the mother offer magical assistance to the heroes,
Both the father and the mother suggest new approaches for the heroes,
Both the father and the mother benefit from the rich rewards of the quests.