Inclusion Criteria:  Self-identify as female Age 18-65 years Speak English or Spanish Physically able to engage in low-to-moderate PA as assessed by the PA Readiness Questionnaire (PAR-Q), or with medical clearance Insufficient self-reported moderate-to-vigorous PA (< 150 minutes/week) Able to enroll with one eligible adult female partner Valid home address in the greater Houston area Have a functioning smartphone and able and willing to send and receive text messages Willing to use the Fitbit app and device Blood pressure reading < 160/100 mm Hg, or with medical clearance  Exclusion Criteria:  Pregnancy or considering pregnancy during the study period, self-reported Currently participating in a program or research study to promote physical activity or weight loss Plans to move outside the greater Houston area during the study period