I don't know a lot anbout breastfeeding, just since I've never needed the knowledge myself...
But I did a quick search and came up with breastfeedings reports that state an average age for weaning is actually often past 2 and a half years. Another source also stated the World Health Orginization recomended children be breastfed for at least two years. (Site here)
So I'd say your friend is being completely healthy for the needs to her baby.
(Smurf got it right before me! )
[This message has been edited by dailicious (edited 07-10-2005).]