Formative research is needed to establish a foundation for obesity prevention research with high-risk, disadvantaged, perinatal adolescents and their offspring. In particular, Black pregnant adolescents in socioeconomically disadvantaged communities represent a high-risk and understudied perinatal population in health research. Adolescent pregnancy (\<20 years) is disproportionately prevalent among Blacks compared with Whites (27.6 and 13.4 per 1,000, respectively) and is a prominent risk factor for obesity. Normal pubertal growth is associated with increased weight in adolescence and Black female and rural adolescents are at highest risk for excessive adiposity. Pregnancy exacerbates preexisting risks and predicates a trajectory of maternal and child obesity. Fortunately, metabolic consequences of increasing physical activity coupled with minimal sedentary behavior can mitigate biological imperils and behavioral interventions targeting perinatal populations have demonstrated efficacy for this approach. Intervention studies to promote physical activity and reduce sedentary behavior among Black, perinatal adolescents in disadvantaged, rural settings may be a promising strategy to prevent obesity and reduce disparities. To this end, investigators conducted formative work in the Teen Mom Study, an exploratory investigation to identify modifiable psychosocial, cultural and environmental determinants of physical activity among pregnant and postpartum adolescents enrolled in Mississippi's Supplemental Nutritional Program for Women Infants and Children (WIC) in the Mississippi Delta. WIC is a federally-funded, state-run public health service providing healthy food and nutrition counseling to low-income women, infants and children at nutritional risk. Public health services like WIC are ideal settings for the prevention and treatment of obesity among high-risk, socioeconomically disadvantaged populations. The Mississippi Delta is a culturally and geographically distinct 18-county rural region of Mississippi that is plagued by decades of persistent poverty, poor health and the highest teen birth rate, which has not declined since 2006, in the United States. Using data from the Teen Mom Study, investigators adapted an existing mobile health (mHealth) intervention to achieve three behavioral goals: (1) limit TV time to less than 2 hours a day (sedentary behavior); (2) take 10,000 steps or more per day (physical activity; tracked using a FitBit provided to each study participant); and (3) do 20 minutes or more of structured activity like prenatal yoga or dance videos per day (exercise). In the #BabyLetsMove feasibility trial investigators aim to conduct a single-arm, 4-week pilot with 20 overweight or obese, Black, pregnant (\<16 weeks) adolescent (15 - 19 years) WIC clients to test the feasibility and acceptability of the intervention. Participants will receive text messages aligned with theoretical behavior change strategies every day of the week for 4-weeks including: 1) four skills texts, which may be a simple text or a text with a link to either a PDF or video; 2) two goal monitoring text messages, which will check-in on the three behavior change goals; and 3) and one text message for participants to report their weight using a BodyTrace scale provided by the study. Text messages will be supplemented with two health coaching telephone calls conducted by the principal investigator; an introduction session in the first week, followed by a problem-solving session in week three. While the study goal is to assess feasibility and acceptability, physical activity assessed using accelerometry, subjective psychosocial constructs, and anthropometric and biomarker measures will be measured at pre- (week 1) and post- (week 6) intervention. To gain additional insight, investigators will use qualitative interviewing with additional adolescents (n=20) to solicit user feedback regarding the acceptability of intervention content (text messages) and materials (PDFs and videos). Finally, in preparation for a randomized pilot trial using an effectiveness-implementation hybrid research design, investigators will conduct a pre-implementation evaluation using quantitative surveying (n=6 surveys) with WIC providers (n=60) to better under the context, culture and climate of WIC (implementation measures identified in the Consolidated Framework for Implementation Research). Investigators hypothesize the #BabyLetsMove intervention materials will be acceptable to adolescents and that conducting a future pilot randomized controlled trial will be feasible. Investigators also anticipate identifying modifiable barriers and facilitators to implementing the intervention through WIC, which will help to design an implementation strategy with a high likelihood for uptake by WIC. If proven to be effective, #BabyLetsMove mHealth intervention may be a scalable approach to increase physical activity among socioeconomically disadvantaged adolescents at high risk for maternal and child obesity.