Despite the plot focusing on a deep dive into the three different women psyche, not one of them has any real personality beyond "old lady (has a bad back)", "small girl (is dynamic, as children are)" and "woman in her thirties (everyone wants to sleep with her, she's so pretty !)".
The murder mystery isn't interesting in itself, the plot twist is kind of predictable from early on and only holds because of the narrator being unreliable.