Just another GR refugee. Other than that, I had a stroke in 2004, and read almost anything I can get my hands on, though I have a particular weakness for history, mystery, and historical fiction.
Patricia Cowan is 88 (or is it 89?), in a nursing home, and both she and her nurses are aware that she is (as they put it) "Very Confused." She insists that there's an elevator, but sometimes there's only a stair lift. Sometimes the bathroom is on the left, and sometimes it's on the right. She forgets a lot, these days.
However, she knows she was born in the year of the General Strike (1926). She knows she was called "Patsy" in her childhood (and always by her mother), and "Patty" at school and Oxford.
But was she latter "Trisha," unhappily married to Mark? Or "Pat," in a loving relationship with Bee?
Was she a sometime English teacher, or a successful author?
Was John F. Kennedy assassinated in 1963, or did he decide not to run for re-election after the nuclear exchange in 1964?
Is there an international science station on the moon, or nuclear missiles?
Most importantly, who are her real children?
Doug, Helen, George, and Cathy?
Flora, Jinny, and Phillip?
After the first few chapters, timelines alternate, after she makes (or fails to make?) a fateful choice in 1949. (It's very clear which timeline is which, from the chapter headings.)
An interesting novel, most definitely alternate history (hint: *neither* timeline is ours), and I think I would call it science fiction, though it's certainly very far from a space opera!