Final answer:
The nurse practitioner would provide resources to promote pumping and likely recommend formula supplementation when the mother experiences reduced breast milk production.
Step-by-step explanation:
During a well-child assessment for a 6-month-old infant, if the mother is experiencing a decrease in breast milk production due to stressors associated with pumping and returning to work, the nurse practitioner will likely provide resources to promote effective pumping and recommend formula supplementation as another intervention. The introduction of solid foods typically begins around 6 months of age as well, so this could complement breastfeeding or formula feeding. Sleep training and speech therapy are not directly related to concerns about milk supply and nutrition at this age.