In her new collection, Mary Rechner dramatizes what it means to these complicated women—mostly mothers—to feel the sand of their identities slipping underfoot, as their primary role becomes helping others develop while they’re still busy doing the same. The nine stories have a distinct ring of truth and a narrow range of experience that feels personal, closely observed. A child’s bare foot isn’t just small, instead “her heels were so close to her toes.” With no frills, no gimmicks, just a gimlet eye and quicksilver prose, Rechner defamiliarizes the mundane and makes it marvelous.

In “Pattern,” Silvia is feeling the sting of deflated hopes—a common theme. The mother of triplets is sewing a dress for her anniversary, wanting “to make something that didn’t get eaten,” and because she used to sew in high school, imagining a glamorous future in her own dresses. Annie, the exhausted mother from next door, lies on the kitchen floor, smoking, doing Pilates, and—at a key point that Rechner almost breezes past—admits she has been “thinking about doing it again,” meaning killing herself. This is a story about how being a mother cuts you into pieces that don’t quite fit together, how a friend can remind you of the girl you were, even bring her back for a spell, and how life with children can be a revelation as well as a chore. It’s utterly realistic, yet a surprising turn near the end feels magical, as the best moments with children (and in fiction) do.

Many of Rechner’s characters are struggling artists: an introverted spoken-word poet reading at a strip club, an actress whose boyfriend died in combat in the Middle East, and a painter using precious child-care hours to see an insulting dentist, while thinking about how annoying it is to potty-train her son. She contemplates giving up on painting and doing a book about poop, since “no one seemed to understand or want her paintings anyway. People love children’s books, and they love poop.”

If so, Rechner is in luck, as her stories can be unapologetically scatological. The hilarious short-short “Four” chronicles the travails of toilet training from the child’s perspective. “Your mom makes you wipe now. All by yourself. No help. She says it’s enough already.” Beneath the silliness is something profound. This toddler can’t modulate his feelings, let alone express them; he is equally desperate for independence and afraid of losing the closeness shared with...