Sylvia Plath was an American poet from Jamaica Plain, Massachusetts. Her very short thirty-year life was riddled with stress and depression. Even though she was a very smart and talented young woman, at the age of twenty she tried to commit suicide. Unsuccessful at this task she continued to write, though her work suffered, and became darker and more depressing. A few years later she married and had two children and one miscarriage.
Still bothered by this miscarriage and her recent divorce in February of 1963, sadly Sylvia succeeded in her second attempt at suicide, by inhalation of natural gas. Sylvia's poem "Last Words" was written in 1961, in the midst of her depression, as you can tell as you read through this almost disturbing piece. Most of her poems toward the end of her life were depressing and having to do with death. Another example of her dark poetry came in the same year, 1961 and was entitled "Mirror". This poem has many references toward death, as does "Last Words". .
In "Last Words" she is directly talking about death to herself, whereas in "Mirror" she is talking about herself being a lake and another woman doing the killing. In this case the woman drowns a young girl in the lake, or "Sylvia". In either case death is obviously on Sylvia Plath's mind, therefore, she inserts it into her work. Also in "Last Words" Sylvia mentions her mirror clouding over. This was probably her motivation for the very comparable poem "Mirror". If you ask me, this young poet's mirror clouded over way too early.