The Growth chart that your pediatrician uses. Does it cover breast fed babies? Because the normal growth rate charts until recently have been based on the weight gains of formula fed babies. It is most definately true that babies and children who are fed cows milk gain weight faster than those who are not. So the chart is not evidence of anything generally.My daughter is 4 years old, was breast-fed for the first 18 months of her life, and weighs over 40 pounds. Try another tack.
Does your daughter eat meat and cows milk? Perhaps you should try another tack.