Economic hardship can affect children's development through child–caregiver interactions, which may mediate cascading effects of other family stress processes. This study examined, simultaneously, the relations of financial strain, caregiver general stress, and child–caregiver conflict—each measured at two time points—with child self‐regulatory outcomes in a high‐poverty sample (age 5–7 years; n = 343). Increase in child–caregiver conflict mediated negative relations between other processes and development of executive function. In contrast, only increase in financial strain had direct, negative association with development of delay of gratification and did not significantly mediate relations between any other process and children's outcomes. Results have implications for understanding effects of family stress on self‐regulatory outcomes and for interventions with low‐income families.