Sabrina Orah Mark’s monthly column, Happily, focuses on fairy tales and motherhood.

The stepmother swings like a light bulb back and forth, causing the mother who is not there to glow. That is her job.

I am a mother, a stepmother, and a step-stepmother because I am my husband’s third wife and he has daughters from his first marriage and a daughter from his second. And I am a mother-mother to our two sons. “This isn’t one of your fairy tales,” my husband once said to me during an argument. He didn’t mean Disney, he meant Grimm. He meant I was stowing myself in the body of a fairy-tale stepmother and setting sail.

When all my husband’s daughters are in our house at once, I grow very small. The weight of those girls who are not mine tilts the house and slides me toward the door. The weight of my sons slides me back in. Up and down goes this seesaw. My husband takes no turns. He grows weightless and blurry.

On weekends, my seventeen-year-old stepdaughter comes out of her bedroom in the early afternoon in a thick white robe. She moves slowly, like a gathering cloud. My sons worship her. She is soft and kind, and they scramble all over her body like mice. “Play with us,” they beg. She yawns. Shuffles into the bathroom. They wait by the door. Often she is in there for a long, long time. Her name is Eve, like the first woman on earth.

I love my stepdaughter, but I don’t love being a stepmother. It’s grim work. If we stood side by side, Eve and I, and looked into the mirror, it wouldn’t be our reflections staring back at us. It would be something wild and cruel. A discarded mother skin. A punishment for loving what doesn’t belong to you.

When there is a stepmother in a fairy tale, it’s because the mother is dead. She is ash buried under a tree, or she is looking down from heaven, or she is dead from childbirth. She is good and beautiful, but she should’ve known better than to have pricked her finger and let three drops of blood fall onto the snow, unleashing a metaphor for impurity. Because out of this metaphor grows a stepmother. A corpse flower in a field of daisies. A blooming shadow.

In Grimm’s “The Juniper Tree,” the stepmother offers her stepson an apple, and when he bends down to take the apple from its chest, she slams the lid so hard “the boy’s head flew off.” She cooks him up in a stew that needs no salt because Little Marlene, her biological daughter, seasons it with her weeping. The stepmother then serves the stew to her husband, who dreamily wonders where his son has gone as he eats him up. The father flickers on and off like an old bulb, while the stepmother stands her ground in harsh light. In Basile’s “The Young Slave,” the stepmother cuts off her stepdaughter’s hair, dresses her in rags, “blackens her eyes,” and makes her mouth “look as if she had eaten raw pigeons.” She tells her husband the child is “only fit for the rope’s end, and that one had to be forever beating her.” And in Grimm’s “Snow White,” the stepmother wants the huntsman to bring back Snow White’s lungs and liver so she can broil them in brine and eat them. It’s easy to dismiss the stepmother as gruesome and cruel. She always is. But I also read the stepmother’s desire to tenderize, serve, and cook the child as a way to replant the child into the body of the family. It’s a way for the stepmother to grow the child of another in her own soil. It’s about repossession and root. I get it. I do. I mean, metaphorically.

I wear my sons’ names around my neck on a thin gold chain, but I don’t wear my stepdaughter’s. A friend cheerily tells me to add her name. “It would make her so happy!” My stomach turns. “I don’t know if her name is for me to wear.” I am either a thief or I am cold-blooded. “Her mother isn’t dead,” I say. “Her mother has a neck,” I say.

“A monster,” writes Colson Whitehead, “is a person who has stopped pretending.”

The stepmother is subterranean. In Robert Coover’s Stepmother, she lives with her condemned daughter in Reaper’s Woods with “witches, murderers, robbers, dwarves and giants, savage beasts, elfin angels, fortune-seeking boys and terrified girls, poor woodcutters, adventuresome tailors, lost minstrels, prophesying birds and bewitched frogs.” She lives where things are both rooted and unstable, where “not even stones or sewing needles can be trusted to be what they seem to be,” where bones sing and pots talk. She is a shape-shifter. She is both insider and outsider. “She has been wrongly blamed for evil done by natural mothers and weak or wicked widowers and is generally suspected of all crimes committed, even of crimes not committed but imagined.” My stepdaughter loves me, I think, but through a mother-ish fog. To stay comfortable she must dress for two weathers: a sundress (mother) and a wool coat (stepmother). Our best conversations happen alone in the car. In a blur of transparency. With no windows open.

Should I even be writing any of this down? Am I committing a crime? I imagine my husband’s daughters’ mothers arriving in the middle of the night, throwing a sack over my head, and tossing me into the river. The earth’s first mirror.

In Grimm’s first edition of “Snow White,” there was no stepmother. She was added in 1819 so that any anger a child might have for her real mother could be sifted out and placed inside her. Like the lentils Cinderella’s stepmother commands her to separate from ash, the Brothers Grimm separated love from anger and good from evil. Originally it was the mother who was jealous of her beautiful daughter. Originally the fairy-tale mother was two things at once. But now the real mother is dead and pure.

I love to clean. “She has,” I overheard one of my husband’s daughters whisper once, “a cleaning problem.” Even as a child I loved to clean. At sleepaway camp I would skip evening activities to be alone in the bunk and sweep. I like sorting. I like to disinfect and straighten, and I love a box. My first two books are collections of prose poems. Each poem is a box. Tidy and justified. After I got married and had children, the poems got bigger. Tore at the edges. Like my stepdaughter growing out of her dresses, the poems swelled and lengthened. They turned into stories. What once was sealed had spilled opened.

“The prose poem,” writes Charles Simic, “is the result of two contradictory impulses, prose and poetry, and therefore cannot exist, but it does.” The stepmother is the result of two contradictory impulses, mother and unmother, and therefore cannot exist—but she does.

In Alissa Nutting’s “The Brother and the Bird” (a brilliant reimagining of Grimm’s “The Juniper Tree”), the stepmother “cleaned constantly, bleary-eyed in multiple hairnets, on her vigilant search for the impure.” So often she rolled a vacuum that it begins to seem like a limb, and her hands—endlessly “beneath thick, yellow kitchen gloves”—have been forgotten. What the stepmother is trying to rub out is not the stepchild’s impurity, it’s her own unmotherness. The stepmother can scrub forever, but she can never get rid of what never grew inside her. And because the ashes of the first wife are buried under the juniper tree, she waters it with bleach. I wish I were the only wife. My thirdness is a spot in the house I can never make disappear. When my son Noah was an infant, on old friend of my husband’s stayed with us for a few days. She had known his first wife. “I remember,” she said, “how beautiful she was when she was pregnant. Gliding through the house in a thin nightgown. It was practically see-through. She glowed.” I felt sick. I held Noah tight as if the image of my husband’s first child growing in the body of another woman might make us both disappear.

Mirror, mirror on the wall. Who is the motherest mother of them all?

I am also a stepdaughter. The first time I heard the word whore, I was ten. My mother’s friend leaned down, smelling like rotting chrysanthemums, her eyes flashing, and said, “You know she’s a whore, don’t you?” And yet, the night before my grandmother died, it was my stepmother who washed my grandmother’s soft, dark, fleeing body. This is the opposite of a fairy tale.

Mirror, mirror on the wall. Who is the motherest mother of them all?

The reason why fairy tales last is because they allow us to gaze at ourselves through a glass that is at once transparent and reflective. They give us a double gaze to see ourselves from the inside out and the outside in, and they exaggerate our roles just enough to bring into focus the little pieces of monster that grow on our hearts.

The space between Snow White and her stepmother begins to narrow when she encounters the dwarves who seem to suddenly spill from her like mothers, like children. A magical, two-way birth. As the dwarves surround her, Snow White becomes both their unnatural child and their unnatural mother. This role prepares her for the glass coffin, an image born out of the stepmother’s mirror. Now they are both encased in glass. And, once inside what can so easily shatter, the stepmother and Snow White finally belong to each other.

When I was pregnant I prayed for boys. I imagined the daughters might forgive me if I had boys. If I had birds or mice or anything but daughters.

What falls on the stepmother’s head at the end of “The Juniper Tree” is a millstone. A bird that once was the son—the same son the stepmother cooked and fed to his father—drops the millstone on her head and crushes her to death. What falls on the stepmother’s head is the weight that comes with a child who reminds her she is never enough. What falls on her head is the reminder that she is a hollowed-out woman. A wind instrument that plays a faraway tune. I know this stepmother. I once came so close to her I could smell the poison apple caught in the back of her throat. It smelled like jealousy and fear. Of never belonging. And, ever so faintly, of love.

Read earlier installments of Sabrina Orah Mark’s monthly column, Happily, here.

Sabrina Orah Mark is the author of the poetry collections The Babies and Tsim Tsum. Wild Milk, her first book of fiction, is recently out from Dorothy, a publishing project. She lives, writes, and teaches in Athens, Georgia.