While helping our parents move, Lana and I came across an old photo of ourselves. It shows us at thirteen-years-old, each with an arm slung over the other’s shoulder and huge smiles wearing exactly the same shirt. As we paged through the photo album, we squirmed at this image, and many more like it, of our younger selves far older than most children still dressing in identical clothing.

“How did they let us leave the house like this?” Lana laughed, and turned the page to relieve our mutual embarrassment.

I’d never thought much about why we did it, but now in those pictures I see an instinctive rebellion — a preemptive retort to the dimming of eyes and the searching for words that follows the realization that Lana and I are not twins, not sisters, but step-sisters.

My father married Lana’s mom, Marla, when we were both seven-years-old. We became step-sisters by way of our parents’ choices but we had our own choice to make about what we wanted ‘step-sisters’ to mean. It took us many years to decide.

It started when my father knocked on the door of Marla’s house. My knees were still dirty from soccer practice and my hair was pulled back behind a sweatband. As Marla opened the door, I curled my fingers tight around the leg of my father’s jeans. Lana was standing right behind her mother wearing a pink floral dress. Her long blond hair looked like it had been brushed exactly fifty times on each side by the kind of girl that counts that kind of thing. Her lips had sparkles on them. I hated everything about her.

I sat down on her couch with my arms folded and I quietly observed Lana from across the room looking for silly quirks I could go home and tell Mom about. Things the two of us would repeat and laugh about over late-night ice cream. We both know that these were things said to remind ourselves that no woman would ever replace her as Dad’s wife or my mom and that no girl would ever replace me as Dad’s daughter.

The tradition began soon after my parents’ divorce. I told Mom about how I heard Dad’s new girlfriend, Cindy, fart in the car. Her nickname became ‘Windy Cindy.’ And it happened again when I told Mom that Dad started dating a woman with black hair and fair skin he called, “V.” Mom said “V probably stood for vampire.” So I was all kinds of excited to make a joke with Mom about the way Lana left her pinky out when she held her cup, but when I did, Mom’s response didn’t have its usual levity. She squatted down in front of me, looked me in the eyes, and said, “That woman will never be your mother. And that girl will never be your sister. You hear me?”

And without a hesitation, I said yes. She knew that Dad introducing us to his girlfriend’s kids meant that things were getting serious. And Mom was right. Because soon Marla and Dad got married and Marla and Lana moved in with us at Dad’s house.

I made Lana sleep on the floor even though I had a king-sized bed. I made Lana use the downstairs bathroom so she wouldn’t make my stuff smell like perfume. And then I would go back to Mom’s house and tell her all about it and Mom would feed me a scoop of Phish Food ice cream out of the carton and laugh and say, “aren’t you so happy you have me?”

And I was. Mom was my everything. She was the person who fed me ice cream out of the carton and let me miss school to paint my room in bright colors. The person who reminded me that love and family was flesh and blood. That Marla and Lana would never be able to share those things with me. How traitorous it was for Dad to give it away so easily.

Which is why when when I was nine-years-old and Mom died, I thought I would die too. Everything went hollow and empty when Dad told me the news. He said that it was a car accident; a tragic but uncomplicated outcome of car meeting telephone pole. He hugged me but didn’t cry.

It didn’t occur to me to ask why her car met that telephone pole. What happened in the days and weeks and months and years before it. I just latched on to the simple truth that terrible things could happen for no reason at all. Even to my mother. I cried so hard that my ribs ached. I did it in the middle of the night with my ear against my bedsheets and a pillow over my face to muffle the sound. I felt alone all the time.

But, slowly, getting into the simple routines of siblinghood with Lana helped me to not feel so alone. We began by building forts and dressing up our brothers. Soon we were brushing our teeth at the same time as we got ready for bed. Styling each other in front of the mirror and requesting two of the same shirt when Marla took us shopping. We started baking cookies together late at night. We liked to see how fast we could stir the batter without our spoons meeting. And when they did, we giggled like little girls with our hands over our mouths to keep our laughter from waking up the rest of the house.

From time to time, I considered whether enjoying my time with Lana meant betraying Mom. But I brushed the thought aside. Lana was bringing new light and happiness to my life and I needed her. I clung to it for years.

Until some time after my fifteenth birthday when Dad called me into his room. He looked up from the floor and told me there was more to Mom’s accident than car meeting telephone pole. He told me there were opioids, and addiction, and failed trips to rehab. As my father spoke, the reel of memories of my childhood played through a prism — each memory was now distorted by my knowledge of her addiction. She wasn’t perfect and her death wasn’t reasonless at all.

I felt robbed of the story of my life. Stripped of the illusion of uncomplicated truths. My happiness, all of it and all at once, felt fraudulent. I walked back to my room with my father’s words curled so tightly around my throat that I could no longer speak. Lana asked me if I was okay, but I couldn’t answer. She, too, was part of the lie of my life and my happiness.

I disentangled my wardrobe from Lana’s and stopped following her downstairs for cookies. I stopped talking to, or even looking at, Lana at all. Still, each day after school, Lana came into my room and asked me if I was okay. She asked if I needed anything. If I wanted to join her for our previous daily routines of an afternoon snack or episode of Law and Order. But without a word, I would slam the door in front of her.

Eventually, I had become so distressed Lana’s visits that I punched a hole in the wall of my bedroom. I pounded my knuckles into the drywall over and over and over again until they bled. My knees buckled beneath me and I crumpled to the floor. Lana came straight back into my room, stood over me, and stared right into my eyes. “You have to talk to me,” she demanded. I knew she was right.

It wasn’t long before, without ceremony, I asked Lana when we could make cookies next. “Tonight,” she said, smiling, but not too much. It was dark and still in the kitchen as we quietly added flour and sugar and milk and eggs into a mixing bowl. Lana brought her spoon into the batter with focus and composure at first. But then her eyes lit up and she pushed her spoon around and around the bowl as fast as she could. I plunged my spoon into the mix next to hers, and when they clanked together, we laughed again like little girls.

Soon, we were back to regular sibling stuff, now as teenagers. Devising clever ways to break curfew. Comparing notes on first kisses. Alternating classes we did homework for and swapping notes. (We surprised our parents when we graduated high school with the same GPA to the one hundredth decimal point). We would often meet in our shared bathroom before school in the morning unintentionally having chosen the same outfit. We never changed.

When I got dumped for the first time, it was Lana’s arms I went running into. She took me into our backyard where we built a roaring fire and burned the love notes he had written me. When Lana got her driver’s license, she picked me up and we drove through the empty roads of our neighborhood with the windows down singing duets of musicals we loved at the top of our lungs. It is one of my happiest memories.

With Lana, I felt permission to be happy again. Permission to relinquish a view of family and love that was too narrow to accommodate both Lana and my mother. With Mom, it was the kind of love I was born with and would be a part of me forever. Even through confusion. With Lana, it was a kind of love you worked for in a way your flesh and blood would never ask you to work. But it turned into a love that was big and deep and sprawling.

Today, I live in San Francisco and Lana lives in Manhattan. I keep a photo of us next to my bed. In it, we’re walking towards the stage for our fifth grade graduation. We are wearing the same long white dress with matching thick white headbands across our heads. We were debunking the myth of step-sisterhood. Reminding the world that even though we would never share genes, we could still share clothes and secrets and a bed at night. Reminding ourselves that our story started with the question of who we wanted to be to one another.

Eventually and relentlessly, we chose our own version of sisterhood. And we wanted to prove it.

Words and Spreadsheets. Spreadsheets and Words.