With her children's blatantly archetypal names, Clora's story is one that should be treated on different levels, including at least the mythic level. This means that perhaps the story should be seen as a systemic depiction of life for a slave in American slavery, instead of being seen as a particular story alone. One interesting consideration might be why Clora blatantly prefers her daughter, "Always," to her son, "Sun."
First, the names should be treated for their mythic properties. The son and daughter are a portrayal of masculine and feminine elements. The sun, which rises and sets each day, to rise again reborn from the horizon, symbolizes masculine energy, and the daughter's timeless, eternal quality is symbolized in her name, "Always." For the mother to prefer the daughter to the son is a way of saying that she prefers the eternal quality of life to the physical reality of her situation.
Each child represents a cosmic point of view. The son, with his daily illumination, represents the waking consciousness that we might call "real life." The claim of the novel is clearly that, even through Clora's suicide, she is able to transcend that life to belong in the realm of "Always." The promise is a kind of eternal life. Although the mythic implication of this verges on philosophy, the literal implication is clear; through the improved fates of her children throughout time, Clora's life and suffering are redeemed as she watches over them from death.