"Elegy for Jane" is, well, an elegy, so death is going to come up. Much of the poem is spent remembering Jane as she was in life. But the core of the poem deals with the speaker's feelings about the death of a young, vibrant woman, Jane, and his inability to reconcile his feelings for her with societal expectations.
Nice try, Ted. "Elegy for Jane" is less about mourning Jane's death than it is about Roethke's fear of death.
Roethke tries to get over Jane's death by connecting her to all the living things he is surrounded with. It doesn't work.