The material well-being of families with children is the basis of the State family policy. In addition to the socio-demographic characteristics of households (children, age of children, number of parents, etc.) that affect the material well-being of families, an important criterion is the state of the household budget in high-cost periods of the life cycle. The authors developed a list of goods for two events when the family budget can be under serious pressure – the birth of a child, the first-grader to school. We also estimated what proportion of the family budget was spent on these sets in families with different numbers of children. Depending on the number of children in the household, the cost of a newborn set is equivalent to 1.4-2.5 monthly income per family member, the cost of a first-grader set is 1.2-2.1. The share of costs, depending on the number of children in the household, for the set of a newborn is up to 40%, for the set of a first grader – up to 34%. As one of the tools for assessing the financial situation of families with children in Russia, we propose not only to introduce a relative price in household budget expenditures but also to estimate the average consumer price indices for sets of goods for children. The results of the study showed that there is significant differentiation in the cost of a newborn and a first grader sets between regions. In most regions, the growth in prices on goods included in the considered sets was higher than the indicator of general inflation and inflation in the group of non-food products. At the same time, the rate of increase in the cost of a newborn's set is higher than that of a first grader's set. Monitoring the inflation of sets of children's goods can be used as the basis for indexing event-related benefits and payments within the framework of state family policy at different levels. Currently, related payments cover between one-third and one-half of the newborn set cost and the first-grader set cost.