I just finished "The Weird Sisters" by Eleanor Brown and just loved it. It's about three adult sisters, daughters of a pedantic Shakespeare professor (hence the title), each with a crisis of her own, and an ailing stay-at-home mom, learning to find how they each fit into the family as adults.

It's totally NOT about my sisters and me, but there are enough parallels (probably common to any family of three sisters and a mother and father who've stayed married) that it was extra engaging to me - but I think any woman with a sister would find some home truth in this novel.

The conceit of the book is that it's narrated by the sisters collectively as a sort of Greek chorus. Each individual gets to speak in her own voice, but the whole history of their growing up together is always present. It doesn't necessarily sound like it would work, but it does.