The goal of this prospective study was to identify effects of birth order on breastfeeding self-efficacy, parental-report of infant feeding behaviors, infant non-nutritive sucking and oral feeding skills in full-term infants at 3-months. Mothers were separated into primipara and multipara groups, and infants were grouped into siblings and no siblings groups. Parents completed the Breastfeeding Self-Efficacy Scale-Short Form, and Neonatal Eating Assessment Tool-Breastfeeding and Bottle-feeding scales. Non-nutritive sucking was assessed using a custom research pacifier and researchers completed the Oral Feeding Skills scale to assess feeding performance. Fifty-six mother-infant dyads (55% male) were included. Primipara mothers reported significantly lower breastfeeding self-efficacy and more feeding problems across breast and bottle-feeds on the Neonatal Eating Assessment Tool. There were no significant differences in non-nutritive sucking or oral feeding skills between infant groups. First-time mothers require more infant feeding support as they exhibited lower breastfeeding self-efficacy and reported more problematic feeding behaviors.