A 24-month-old girl is evaluated at a well-child visit. She walks and runs, climbs stairs with support, and uses 50+ words in short phrases. However, her parents report that she does not follow two-step commands (e.g., 'Pick up the toy and put it in the box'), cannot point to body parts when asked, and does not understand simple questions like 'Where is your shoe?' Her hearing was normal on newborn screening. What is the most appropriate next step in management?