my daughter is 5.5 months old, she doesn't drink enough milk and she is not gaining enough weight. what to do?

A. Hello good morning !! By 5-6 months babies double their birth weight ,the ideal weight should be 5-7.5 kg . If the baby's weight is less according to the age and birth weight then there might be less intake of milk or sleep. Sleep also impacts on growth,check the baby is getting 13-18 hours of sleep a day .