I think Lanfear killed Else - Edit 1
Before modification by Sidious at 09/08/2010 12:02:59 PM
And Lanfear had the entire family under compulsion. I'm wrong, probably. 
Else liked Mat and Rand, and she was expelled from the Tower because she spent so much time going after men. When Mat saw her again he was surprised by her aloof attitude and her effort to avoid physical contact.
Lanfear probably killed Else and used her for a disguise.