Parents' responses to infants' signals are an essential contributor to healthy child development. Therefore, a better understanding of the factors that influence parents' responses can guide policymakers and healthcare professionals to effectively empower and support parents in ways that will promote their children's development. This study examined whether three factors-marital status, social support, and family income-predict changes in mothers' physiological activity and behavior during stressful mother-infant interactions. Ninety-two mothers and their 7-month-old infants were observed playing with their infants for two minutes (play episode), not engaging with their infant while maintaining a blank facial expression for two minutes (still-face episode), and resuming normal interactions with their infant for two minutes (reunion episode). Mothers' behaviors and their autonomic nervous system responses during these three episodes were recorded. Statistical analyses revealed that mothers exhibited changes in their behavior and autonomic responses during the three episodes. Specifically, mothers' social positive engagement decreased from the play to the reunion episode, their respiratory sinus arrhythmia (RSA) levels decreased from the still-face to the reunion episode, and their heart rates decreased from the play to the still-face episode and then increased during the reunion episode. In addition, family income predicted changes in maternal RSA levels. Mothers with low household incomes exhibited larger increases in RSA from the play to the still-face episode than mothers with high household incomes. This study conveys the complexity of maternal responses to infant distress and the importance of understanding how various factors, such as conceptual cues and socioeconomic circumstances, may influence maternal behaviors and physiological regulation during the Still-Face Paradigm. By examining these aspects, we are contributing to our knowledge of early child development, enhancing maternal responsiveness, and promoting positive parent-child relationships.