Among Others — Jo Walton

Startling, unusual, and yet irresistably readable, Among Others is at once the compelling story of a young woman struggling to escape a troubled childhood, a brilliant diary of first encounters with the great novels of modern fantasy and SF, and a spellbinding tale of escape from ancient enchantment.

Raised by a half-mad mother who dabbled in magic, Morwenna Phelps found refuge in two worlds. As a child growing up in Wales, she played among the spirits who made their homes in industrial ruins. But her mind found freedom and promise in the science fiction novels that were her closest companions. Then her mother tried to bend the spirits to dark ends, and Mori was forced to confront her in a magical battle that left her crippled--and her twin sister dead.

Fleeing to her father whom she barely knew, Mori was sent to boarding school in England -- a place all but devoid of true magic. There, outcast and alone, she tempted fate by doing magic herself, in an attempt to find a circle of like-minded friends. But her magic also drew the attention of her mother, bringing about a reckoning that could no longer be put off...