All Grown Up by Jami Attenberg

From Kirkus, because I agree with them and they say it so well:

Deeply perceptive and dryly hilarious, Attenberg’s (Saint Mazie, 2015, etc.) latest novel follows Andrea Bern: on the cusp of 40, single, child-free by choice, and reasonably content, she’s living a life that still, even now, bucks societal conventions. But without the benchmarks of “grown up” success—an engagement, a husband, a baby—Andrea is left to navigate her own shifting understanding of adulthood.
“Why is being single the only thing people think of when they think of me? I’m other things, too,” Andrea says, much to the delight of her therapist, who wants to know, then, what exactly those other things are. She is a woman, Andrea says. A designer who works in advertising; a New Yorker; technically, a Jew. A friend, she tells her therapist. A daughter, a sister, an aunt. Here are the things that Andrea does not say: she’s alone. A drinker. A former artist. A shrieker in bed. At 39, Andrea is neither an aspirational figure nor a cautionary tale of urban solitude. She is, instead, a human being, a person who, a few years ago, got a pair of raises at work and paid off her debt from her abandoned graduate program and then bought some real furniture, as well as proper wine glasses. And still she does not fully compute to the people around her, people whose “lives are constructed like buildings, each precious but totally unsurprising block stacked before your eyes.” Everyone is married or marrying, parenting or pregnant, and it’s not so much that she’s lusting after these things, specifically—neither marriage nor babies is her “bag,” anyway—so much as it’s that her lack of them puts her at odds with the adult world and its definitions of progress. Structured as a series of addictive vignettes—they fly by if you let them, though they deserve to be savored—the novel is a study not only of Andrea, but of her entire ecosystem: her gorgeous, earthy best friend whose perfect marriage maybe isn’t; her much younger co-worker; her friend, the broke artist, who is also her ex-boyfriend and sometimes her current one. And above all, her brother and his wife, whose marriage, once a living affirmation of the possibility of love, is now crumbling under the pressure of their terminally ill child.
Wry, sharp, and profoundly kind; a necessary pleasure.