I punished myself when I lost patience, when I bribed, when I wanted to flee. I punished myself for resenting Lily when she came into our bed, night after night, which wasn’t actually a bed but a futon we pulled out in the living room. Every feeling I had, I wondered: Would a real mother feel this? It wasn’t the certainty that she wouldn’t, but the uncertainty itself: How could I know?

I had imagined that I might feel most like a mother among strangers, who had no reason to believe I wasn’t one, but it was actually among strangers that I felt most like a fraud. One day early in our relationship, Lily and I went to a Mister Softee, one of the ice cream trucks parked like land mines all over the city. I asked Lily what she wanted, and she pointed to the double cone of soft serve, the biggest one, covered in rainbow sprinkles. I said, Great! I was still at the Disney Store, still thrilled to find the sled set, still ready and willing to pass as mother by whatever means necessary, whatever reindeer necessary, whatever soft-serve necessary.

The double cone was so huge that Lily could barely hold it. Two hands, I would have known to say a few months later, but I didn’t know to say it then. I heard a woman behind me ask her friend, “What kind of parent gets her child that much ice cream?” I felt myself go hot with shame. This parent. Which is to say: not a parent at all. I was afraid to turn around. I also wanted to turn around. I wanted to make the stranger feel ashamed, to speak back to the maternal superego she represented, to say: What kind of mother? A mother trying to replace a dead one. Instead I grabbed a wad of napkins and offered to carry Lily’s cone back to our table so she wouldn’t drop it on the way.

As a stepparent, I often felt like an impostor — or else I felt the particular loneliness of dwelling outside the bounds of the most familiar story line. I hadn’t been pregnant, given birth, felt my body surge with the hormones of attachment. I woke up every morning to a daughter who called me Mommy but also missed her mother. I often called our situation “singular,” but as with so many kinds of singularity, it was a double-edged blade — a source of loneliness and pride at once — and its singularity was also, ultimately, a delusion. “Lots of people are stepparents,” my mother told me once, and of course she was right. A Pew Research Center survey found that four in 10 Americans say they have at least one step relationship. Twelve percent of women are stepmothers. I can guarantee you that almost all these women sometimes feel like frauds or failures.

In an essay about stepparents, Winnicott argues for the value of “unsuccess stories.” He even imagines the benefits of gathering a group of “unsuccessful stepparents” in a room together. “I think such a meeting might be fruitful,” he writes. “It would be composed of ordinary men and women.” When I read that passage, it stopped me dead with longing. I wanted to be in that meeting, sitting with those ordinary men and women — hearing about their ice-cream bribes, their everyday impatience, their frustration and felt fraudulence, their desperate sleds.

In the methodology portion of her “Poisoned Apple” study, Church admits that she disclosed to her subjects that she was also a stepmother before interviewing them. After an interview was finished, she sometimes described her own experiences. Many of her subjects confessed that they had told her things during their interviews that they had never told anyone. I could understand that — that they somehow would feel, by virtue of being in the presence of another stepmother, as if they had been granted permission to speak. It was something like the imagined gathering of unsuccessful stepparents, as if they were at an Alcoholics Anonymous meeting in a church basement, taking earned solace in the minor triumphs and frequent failures of their kind: a kind of kin.

The decision to call the stepmother Mother, or the decision not to call her Mother, is often a dramatic hinge in stories about stepmothers, a climactic moment of acceptance or refusal. In a story called “My Step-Mother,” published in The Decatur Republican in 1870, a young girl regards her new stepmother with skepticism. When her stepmother asks her to play a song on the piano, trying to earn her trust and affection, the girl decides to play “I Sit and Weep by My Mother’s Grave.” But lo! The stepmother is undeterred. She not only compliments the girl on her moving performance; she shares that she also lost her mother when she was young and also used to love that song. The story ends on a triumphant note, with the daughter finally calling her Mother, an inverted christening — child naming the parent — that inaugurates the “most perfect confidence” that grows between them.