It is a personal decisionI let my 3 yr old dd start nursing again when her baby sis was 6 months old. I did it because she seemed like she needed to *know* that she was still my *baby*. She nursed for a year when I weaned her by choice because she was sucking the life out of me! (she had just turned 4) I continued to nurse her sister for another year and a half until she was 3 years 2 months. I did enjoy tandem nursing, and I would not change that at all.