Reforms of tax-benefit system of financial support for families with children have a broad range of consequences. In particular, they often imply trade-offs between effects on income redistribution and work incentives for first and second earners in the family. Understanding the complexity of the consequences involved in reforming family policy is crucial if the aim is to “kill two birds with one stone” namely to reduce poverty and improve incentives to work. In this brief, we illustrate these complex trade-offs by analyzing several scenarios of reforming financial support for families with children in Poland. We show that it is possible to create incentives for second earners in the family to join the labor force without destroying the work incentives of the first earners. Moreover, the same reform would allocate resources to families with lower incomes, which could result in a direct reduction of child poverty.