So far, no reason has been given for her death.
With no experience courting a potential bride - his sexual experiences confined to slaves and whores - Hammond ultimately chooses his cousin Blanche for his wife in what would not be considered a courtship in its true sense.
Concurrently, Hammond also purchases Mede, a Mandingo, as a slave, something Warren had always wanted because of their physical strength.
.
Blanche, in return, takes her anger out on Hammond in the only way she knows how.
Maybe it's no accident that that feels liberating.