We hate to be a Debbie Downer, but unfortunately sadness seems to be a much more persistent emotion than happiness. In "Elegy for Jane," once sadness shows up it seems to be just about unshakable. We expect an elegy to be sad, but traditionally they end with the speaker finding some kind of consolation. No such luck in "Elegy or Jane." In fact, by remembering Jane being happy in the first stanza, the gloom of sadness that shows up in the second stanza seems even darker.
Jane should stop waiting around for her daddy to save her and cheer herself up. All she needs to do is change her perspective. Change your perspective and you can change your mood.
"Elegy for Jane" proves that Roethke believes sadness is a more powerful emotion than happiness. Crying for the win.