'Do' shows the fluidity definitions of who is in and of the families of single mothers and discusses how mothers construct, deconstruct, and reconstruct their Nelson (2006) suggests that single mothers respond to the hegemony of the Standard North American Family (SNAF) (Smith, 1993), a family ideal they cannot achieve practice but one that dominates their conception of what a family should be. These single mothers' own mothers-the maternal grandmothers of their children-come to the rescue times of need. Single mothers are quick to replace grandmothers with their new partners, however. These are men whom single mothers would like to see become involved their children's lives. A single mother wants to incorporate a new partner into her definition of her family because it allows a single mother to approximate the ideal, the heterosexual couple, two-parent family norm. The single mother does not question that this family form is best for rearing her children, even though her family can never quite achieve perfection because of the weak tie, indeed the absence, of her children's biological father. It is useful to think about the fragility of family life that is implied by the term family. The argument is that families are constantly being created, destroyed, and recreated. We all include somewhat different sets of individuals definitions of who is our family. No parent is biologically related to the same set of people as is that parent's children. Furthermore, ties beyond biology abound a world where almost half of marriages end divorce, one third of children are born outside marriage, and repartnering is commonplace. I find the social constructionist, emergent nature of family implied the concept of doing family provocative, but I also think there are limits to the usefulness of the concept and the emphasis on instability family definitions that this notion implies. Families may to some extent be done or constructed, as Nelson (2006) suggests, and a single mother may perhaps hold a vision of the family that leads her to minimize grandmother-grandchild ties once a new lover enters her life. But nonetheless, some intergenerational bonds-those between a mother, her daughter, and her daughter's children-seem rather impervious to deconstruction. On one hand, mothers tend not to leave their children. Maternal grandmothers support their daughters and grandchildren and provide a safe haven to which daughters can return when bonds between single mothers and the men their disintegrate. Fathers, on the other hand, do leave their children and consequently, men seem much greater danger of being defined out of families than mothers and grandmothers. Grandmothers' primacy may fade with a new partner-they may recede into the background-but they do not disappear. Margaret Nelson's (2006) title, 'Do' could as easily be Mothers and Daughters 'Do' Family. Women rear children the face of the exodus of men from family life and they do so by bonding across generations. Although the article makes interesting points about mothers' desire to control their childrearing and mothers' eagerness to reconstruct the SNAF by transferring care of children to new partners, what really stands out is the picture of intergenerational exchange and bonds of dependence, obligation, affection, and caregiving. We are left with two questions that are at the heart of the intersection of gender, family, and generation: Why are ties along the maternal line so strong, especially times of crisis? Why are biological ties between fathers and their children often so weak? Gender and Generational Ties In his Burgess Award Lecture, published Journal of Marriage and Family February 2001, Vern Bengtson argued that ... for many Americans, multigenerational bonds are becoming more important than nuclear family ties for well-being and support over the course of their lives (Bengtson, 2001, pp. …