I think that the overall cruelty that is so intrinsic to understanding the themes in "The Lottery" is amplified in seeing how Tessie's family is a part of the savagery. Jackson is seeking to bring out how the terror of the community, the desire to target another, and how social conditions and practices of evil can dehumanize the relationships between family members are all a part of this process. In displaying that the family was a part of what happened, it becomes clear that the full force of the brutal tradition is no display. Jackson wishes to bring forth how cruelty does not end at family lines. When Tessie's own husband and children participate, it is a moment where the reader confronts the abject horror of brutality. It is intended to evoke a reaction from the reader, causing them to question how these practices are in our own history and society to ensure that they do not happen again. The force of such a display is blunted if the family rallies around Tessie. In leaving her to perish at the hands of social cruelty, it is a stark reminder to the reader that avoidance of such a condition is absolute.