A mother brings in her 16-month-old, Brittany, for treatment of an acute illness. During the history, the mother reports that her mother-in-law is...

A mother brings in her 16-month-old, Brittany, for treatment of an acute illness. During the history, the mother reports that her mother-in-law is concerned about the toddler's development. Further questioning reveals the following:

• Brittany was a term infant born vaginally with no intrapartum complications. Birth weight was 8 pounds 1 ounce and current weight is 26 pounds 9 ounces.
• She was breastfed until 12 months of age and now drinks 24 ounces of whole milk and eats table foods daily.
• Physical milestones are as follows: Rolled front to back at 6 months, developed pincer grasp at 11 months, crawled at 8 months, and began cruising at 10 months. She does not walk independently.
• Social development includes mimicking adult behavior, four-word vocabulary (mama, dada, baba, and no), follows one-step commands, and quiets easily when comforted.