The Seaglass Stair — Ash Gray

Wareska is wizenblood, a woman born with magick powers that will, over the course of a thousand years, render her into a shriveled, elf-like creature. When Wareska's teacher dies, she finds herself wandering the wilds with her companion, a horse which can speak with her telepathically. She and the horse live in peace for a time, until a strange, dark sickness sweeps over the land, sapping it of life and color. Rivers run dry and animals shrivel away, as if the very life has been sucked from them. Wareska soon discovers the means to stop the land-sickness and sets off on an adventure to do so, facing down aggressive unicorns, evil spirits, ice-breathing dragons, and traveling through the shadowlands of the dead.
*This is a book written by a woman for women.

Quotes:
Wareska stared thoughtfully into the fire. She knew of the Water Stair. She'd read about it in one of Old Hemfra's books. It was to the east, the far east, in a land known as Sandka Vule. It was a land very far away, and the path between it and lands to the west was fraught with peril after peril: fire-breathing dragons, giants, angry trees -- the occasional angry horde of giant trees -- massive birds of prey, wild men who roamed as exiled criminals, and rogue wizenblood, who used their power for ill. That Shadowmane had wandered so far, only to end up in Lorlas Ru unscathed, was remarkable.

--
:I am Topaz,: the unicorn on the hill haughtily announced, :and this is my vale.:
:I was not aware unicorns could own vales,: Wareska linked.
The unicorn stiffened, and even from this distance, Wareska could see her bright, golden eyes narrow dangerously. :Now you know,: she said with quiet menace.

--
Shadowmane sighed as well. :We had better do what this Topaz commands. Unicorns are jerks when they don't get their way.:

--
:No,: Wareska said at once, :we should go back.: She heard the horse laugh softly into her mind.
:Wareska,: she said in amusement, :it is not like you to ever look back.:
:I look back when sense dictates.:
:It is hard for horses to look back. We don't really have shoulders. I guess we look back over our butt?:
Wareska laughed sadly.

--
:So we'll talk and then you'll eat me?:
:No, Ravensoul. Brunahiem,: the creature said in irritation and swore in the ancient tongue of the dragons. :Do you think me a mere beast? As if dragons only cared for eating and hoarding. Brunahold! As if wizen tasted well anyway. You taste like little donkeys.:
:What do you want then?: Wareska asked wearily. :I'm kind of in the middle of saving the world. You know . . . the world you inhabit.: