Having just finished re-reading her novel The Tiger in the Tiger Pit, I must (once again) proclaim that she is one of the finest novelists writing in English. Take this, from that novel: "The greatest mystery, Elizabeth thinks, is the wildness of the beast within us. At any moment we may move in some primal way, take a mere step in the direction of private desire, stretch an arm: and our claws have left blood in their wake."
When I began writing Yield, my first novel, I had this insane notion that the writing was separate from the story. Hence, I would slap these precious, poetic little interludes at the end of a chapter, thinking okay, I've done what I want with getting the plot where it needs to be, and now I can enjoy myself a bit, maybe write a pretty sentence with the words 'light' and 'face' in it.
Janette taught me that the writing is the story, and the story is the writing. They are not two different things. She manages to write highly-political novels of very intimate circumstances. They are spotted with Shakespearean references, and nods to modern art and philosophy. I wrote once that what I liked most about her books was that they seemed to "be aware of where they are in history." So that the novel is less an island--and more a response, a reaction, a dialogue with the entire scope of art and artforms: music, opera, poetry, painting.
You can read about her at her website, or here on Wikipedia, or read interviews with her here, and here.