She helped Rand a lot more than she helped the Shadow, by gifting him Asmodean for a teacher, something which he desperately needed.

And what did she do to help the Shadow? Pretty much nothing. Moiraine has played her main role already by the time of the docks confrontation and was able to come back when needed.

Don't forget Couladin and the Shaido when judging Asmo, BTW. They caused a whole lot of trouble to the good guys as a result of his machinations.