Breastfeeding: When is the Right Time to Stop?

In a recent article in "Time" magazine a mother in a photograph on the front cover now appearing on Good Morning America shows her 3-year-old son being breastfed almost turning  our and has nursed her other son until he was slightly older.

Being nursed herself till the age of 6. I suppose she is trying to make it that way for her children. But when is the right time to stop? I remember my 3-year-old knowing a lot at that age and is it really the right thing to continue with?

I believe parenting is different for everyone and everyone should have a choice, but breastfeeding is meant for babies in my eyes, I could never see me breastfeeding my now almost five year old child, there are other ways to go about it.

Nursing is a task in itself, I give a lot of credit to parents who have went almost a year or longer, I was told to try a year since my kids both had severe allergies,  but nursing an older child just is weird in itself.