She was raised to the Shawl in a very short time, and then became the White Tower's representative to one of their most important allies. She got Morgase (and Gareth Bryne) to follow Tower priorities, which was apparently difficult (though why is not something I'm too clear about). She overthrew Siuan, she broke the Black Ajah's stranglehold on the Amyrlin Seat. But more importantly, she has been described as formidable several times throughout the series, including by Siuan. Evidently, one cannot compare the perspective of the lost farmboy Rand in The Eye of the World to the perspective of a rival Amyrlin in this chapter, but there has still been a considerable shift in her characterisation. This is itself admitted in the work itself, when Egwene thinks: She joked - joked! - about how she had stolen the shawl from a woman, humiliating her to such an extent that she fled the Tower. Light! What had happened to Elaida? Egwene had met this woman before, and Elaida had struck her as stern, but not tyrannical. Power changed people. It appeared that, in Elaida's case, holding the Amyrlin Seat had taken her sternness and solemnity and replaced them with a heady sense of entitlement and cruelty.