A 18-month-old boy from an urban slum in Mumbai is enrolled in the ICDS Anganwadi programme. His weight is 9.5 kg (between 50th and 75th percentile for age), and MUAC is 13.2 cm. He has no oedema and appears alert. His mother reports he attends the Anganwadi 4 days per week and receives supplementary nutrition (fortified wheat-based take-home ration). On follow-up after 3 months, his weight remains 9.5 kg with no improvement. Dietary recall shows the family's staple diet is rice and lentils with minimal animal protein. Which of the following is the MOST appropriate next step in the ICDS management strategy for this child?