Duration of Breastfeeding
Breastfeeding is halachically encouraged, especially for the first two years of life. Up to the age of two, if a child has ceased nursing, he may resume breastfeeding even if he has only nursed for a few months or has never nursed. Above the age of two and until the child's fourth birthday (or if the child particularly needs it, the fifth birthday), nursing may be continued (but not initiated); however, anytime a healthy child above the age of two does not wish to nurse for 72 hours, breastfeeding may not be resumed. Expressed breastmilk is kosher even for older children or adults.