According to Kinbote (in VN’s novel Pale Fire, 1962, Shade’s mad commentator who imagines that he is Charles the Beloved, the last self-exiled king of Zembla), his note to Line 493 of Shade’s poem (She took her poor young life) is not an apology of suicide:
The following note is not an apology of suicide – it is the simple and sober description of a spiritual situation.