From 1948 to 2015, there was a dramatic increase of mothers in the workforce. The literature demonstrates that mothers tend to work outside of the home while also maintaining most of the domestic roles. However, the literature does not address how these women are able to balance their roles. There is a gap in the literature concerning the relationship between locus of control, perceived supportive factors, income size, and work-life balance for working mothers. The purpose of this cross-sectional quantitative study was to fill that gap as measured by Rotter's Internal- External Control Scale, Satisfaction with Work and Family Balance Scale, Multidimensional Scale of Perceived Social Support (MSPSS), income size, and demographic information. The work and family border theory and the social learning theory were used as the theoretical frameworks. This online study used Facebook to recruit 164 working mothers between the ages of 18-50 with children under the age of 18. Correlations, t tests, and linear regressions were used to analyze the data. The results showed no significant relationship between loci of control on work-life balance. However, perceived support was associated with work-life balance and predicting work-life balance. This study is intended for employers, program developers, and mental health professionals in their efforts to support working mothers in gaining work-life balance. The social change implications of this study are to increase understanding of work-life balance, reduce mental health risks associated with imbalance, decrease job dissatisfaction, absenteeism, isolation, and increase universality and normalcy of the working mother experience.