The Margarets by Sheri S Tepper
One of the books I borrowed from my local library recently was a chunky SF novel (science fantasy?) called The Margarets. Margaret Bain is a lonely little girl, the only child on the research station at Phobos. To entertain herself she creates imaginary selves with different traits and personalities: a queen, a warrior, a healer, a shaman. At major turning points in her life, the separate identities seem to take on a life of their own, even long after she has grown out of them - are they dreams, parallel worlds, or a strange reality? It's interesting to see how different experiences shape each identity in different ways.
On Earth as an adolescent, Margaret faces the ravaged planet for the first time, with its overcrowding and damaged ecosystem which has fallen foul of the body which seems like a kind of interplanetary UN. However, Earth has some friends among the other, older races and their minor gods. When they learn of a threat to humanity, it seems they can't combat it without the help of all the scattered Margarets, each of which is involved on the fringes without realising it.
I did find this novel a little confusing and had to resort to the reference table of Margarets, their locations and associates (which can give big hints to later plot-points so is best approached carefully) but that may be partly because of the bitty way in which I read the first half, ten minutes here and there between other activities. I also had to grit my teeth through the first part: the whole novel is first-person, from the point of view of one or other of Margaret's identities, and since she's a child as the story begins, that part is written from a child's perspective and it grated a little. Overall though I enjoyed it, I thought the story was interesting and unusual, strong enough to pull me past my reservations on the style (a bit soft-focus and girly in places, not my usual fare though I'm not saying I never read anything like that). Mainly well-written, though a shiftless redneck family with members named Billy Ray, Joe Bob, Billy Wayne, Lou Ellen etc seemed a bit stereotypical, as did the dialogue of the pseudo-West-African tribes on one of the planets.