Wind oozing thin through the thorn from norward, And the woman calling. (15-16)
And yet! In the final lines of the poem, the woman's voice continues to call to the speaker. Maybe she's dead, but she lives on in him? Maybe he's deranged, and is hearing voices? Maybe his memories are so powerful that they overtake him? Whatever you think, it's clear that even though the woman is dead, she's alive in the speaker's memory.