Who is Nynaeve al'Meara from A Crown of Swords and what is their importance?

Nynaeve is an Aes Sedai who is also very young. She can only channel when she is angry for the first part of the book. It is only after she is attacked by Moghedien and Lan saves her that Nynaeve is able to break her block and can channel at will rather than when she is only angry. Nynaeve is very harsh with Mat and the two do not get along on any respects.