"She is a great woman."
Translation:C'est une femme remarquable.
I think I've found the answer here: http://french.about.com/library/weekly/aa032500.htm
Il/Elle est un(e) XXX is not French, you have to say C'est un(e) XXX.
I wouldn't translate it by bonne, and never in this sentence because "c'est une bonne femme" is pejorative and "c'est une femme bonne" is slang (see http://www.wordreference.com/fren/bonne for the meaning if you want).
I (French native speaker) don't think there is any context where you can translate great by bon/bonne, but I can't pretend to be sure: too many meanings of great, see http://www.wordreference.com/enfr/great).