B.S.
In my opinion and experience it is best to let the child wean when they are ready. Then they are emotionally secure, and there is no physiological engorgement as it is very gradual. The average age for weaning in the world is age 5 and we really force/push our kids here in this nation. All babies have a sucking need that ends at different times. There is no need to rush what is natural unless you have to go back to work and are unable to be with the child. The child will be healthier both emotionally and physically if you let them wean when they are ready.
B. S. RN CCM former lactation consultant and La Leche League member