Social support plays an important role in the well-being of new mothers and their infants. Lack of social support is a risk factor for postpartum depression (PPD) in new mothers. The long term goal of our research is to design and develop a socio-technical system to facilitate social support for new mothers. To this end, we identified common needs of new mothers using semi-structured interviews and discussions in closed Facebook groups consisting of new mothers. Informed by the identified needs, we designed and developed the prototype of a mobile application called Mom's Circle, in which a new mom can enroll a community of helpers who agree to help her with common instrumental needs. In this paper, we discuss key findings from the needs assessment study, an overview of Mom's Circle App and results from the initial field deployment of Mom's Circle.