When Grandma says she's seen a tiger in the garden, Nora doesn't believe her. She's too old to play Grandma's silly games! Everyone knows that tigers live in jungles, not gardens.
So even when Nora sees dragonflies as big as birds, and plants that try to eat her toy giraffe, and a polar bear that likes fishing, she knows there's absolutely, DEFINITELY no way there could be a tiger in the garden.
Could there?