Equity-denied families report barriers to accessing parenting supports, and online programs have the potential to improve accessibility. First Pathways is a digital parenting program designed to promote parent-child interactions and children’s development by sharing parent-child interactive activity ideas and knowledge of how these activities support children’s brain development. We recruited equity-denied families from community organizations and via snowball sampling to investigate the effect of playing First Pathways on parent-child interactions and child development for parents and their children aged 3–36 months. We also examined predictors of game play. Parent-child dyads participated in a 2-month randomized controlled trial pilot study. The First Pathways group received daily reminders encouraging game utilization for one month. Parent-child interactions and children’s development were reassessed at 1- and 2-months. Although no significant group differences were found between the First Pathways and waitlist control group, the quartile of dyads who played First Pathways the most (n = 13) demonstrated significantly greater improvements in parent-child interactions compared to dyads (n = 12) who played the least. Moreover, total game play over the 2-month study was significantly correlated with improvements in parent-child interactions. Dyads were significantly more likely to play First Pathways while receiving reminders, and early play predicted later play. Dyads who showed the greatest reciprocity in their interactions (i.e., balanced back and forth serve and return exchanges) at baseline were most likely to have greater game play. Online programs have potential to support parent-child interactions and child development for equity-denied families; additional research is needed to understand facilitators/barriers to early engagement.