This a short story about an unnamed pioneer/settler woman in charge of a group of people living in a cave. Time keeps shifting outside the cave, and they end up in different eras/epochs in history. She is also making some sort of tapestry(?) which she realises is a map or guide to where they'll end up next.
We thought this might have been a Stephen King story but couldn't find it. It was read in the last few years as part of an anthology (in paperback, pre e-readers), but unfortunately we've no idea when it might have been published.
Many thanks for any help.