Question

How and why did the narrator's brother keep her away from the shed

Answer 1

Answer:

because the poet's brother doesn't want the poet to come inside the shed and wants the shed to be his den

Answer 2

Answer: The narrator's brother fabricates a story about a ghost inhabiting the shed in order prevent the narrator from entering the shed and to keep the shed all to himself. The narrator starts believing this story and imagines someone staring at him every time he passes by the shed.