My grandparents and I stood quietly in the lift as it crawled up to the third floor, where my new dorm room was located.
It was move-in day and to say I was out of my element was an understatement.
I was in a city for the first time. I'd hardly ridden in a lift before I went away to college because there wasn't a need for it in the rural town where I grew up.
Unpacking all morning had left my grandparents unusually tired.
In those few minutes, a girl looked over at me and asked where my parents were.
I felt my throat close at her inquiry. "We're her parents," Grandma snapped.
I swallowed heavily and looked at my feet, avoiding all eye contact.
Maybe Grandma hissed at the girl to dissuade any more questions, but I didn't rationalise it this way.
What I heard was exposure and I felt ashamed at how unusual I was. I was an orphan without any siblings. Family, for me, had always been defined by two ageing grandparents.
On campus, my peers appeared to have the family I spent my entire childhood dreaming of. Everywhere I turned, I saw families laughing or, more simply, enjoying their time together. My youth was an isolating existence, always, but the feeling was particularly pronounced in the lift that day. I hated how we were so different.
In hindsight, I shouldn't have felt so alone. There are more than 2.6 million "grandfamilies", as we are dubbed, in the United States, according to the US Census Bureau. Sometimes, my particular situation is more formally called kinship care.
What both labels hide is an inherent sadness at the family's core. Nearly six million children are growing up with their grandparents and the challenges these families face are steep.
Grandfamilies come together for myriad, but never happy, reasons. We are formed out of necessity or afterthought. Death, drugs, incarceration or - as in my situation - parental abandonment create these family units. And when a family comes together over turmoil, the muck can't easily be scrubbed away, no matter how okay things appear on the outside.
I grew up dreading the day my grandparents died. They were old, this was my reality.
Grandpa died right before I met the man I married and I managed to hang onto Grandma until early this year. When she died, I couldn't shake the feeling I was now a stray animal, set to wander aimlessly from now on.
Grandma was 91 and in poor health, yet her death still came as a shock and huge loss. That's because my grandmother was a hybrid - Grandma but, really, more mum. Grandma was my last anchor to the past and I now felt untethered.
I spent the better part of my life angry at Grandma because of my rough childhood. She grew up on a homestead in south-eastern Colorado during the Great Depression and she was a tough woman because of it.
There wasn't affection in our home and she didn't shower her children with compliments. She never told me "I love you", even though I know she did.
It wasn't until Grandma died that I understood the immense sacrifice she and Grandpa made in spending their retirement years raising a third child - their daughter's child, the result of an affair with a married man two decades older.
Instead of selling their home and buying a motor home to tour the country, they worked years longer - Grandma as a cashier at the local grocery store and Grandpa at the dry cleaners - to support their only grandchild.
My mother left to pursue a journalism career and, because of this, my family was saddled with constant emotional challenges. Anger and rage towards my mother filled my teenage years, but Grandma never wavered in defending her daughter.
"She's a good mother," Grandma said to me once. My mother had been dead for almost 20 years at this point and I was pregnant with my son.
"I would never throw my kid out like an old sweater," I shot back.
She never said her daughter's actions were wrong or that I didn't deserve to be treated this way. We would never agree on this. In the end, though, it didn't matter.
A few months before she died, I called and we talked about my parents in a rare and candid conversation. "Oh, don't think back on that, there's nothing there but sadness," she said. "Focus on what's ahead, that's what is important."
As Grandma aged and her health failed, I started experiencing anticipatory grief.
When she broke her hip, I flew to be at her hospital bedside. I'd become accustomed to receiving messages that she was in the hospital for one reason or another. I'd cry and go a night without sleeping, sure this time was it. I went into work with puffy eyes, waiting for the word Grandma was dead.
For three years, she rallied. Until the last time, when she didn't.
After her death, I searched online for information on grieving. I'd done this before, but this time, I became consumed reading about the path to healing.
Among those many searches, which have since blurred together, one comment I stumbled across stayed with me: Grief is the nectar that purifies our relationships.
I'm not yet 40 and my family of origin is gone. It's a strange feeling. Sometimes, it's sad, but it is also freeing. If there is one thing Grandma taught me by example, it's this: It's all right to be different. But it took me years to heed this lesson.
Grandma will always be my mother. And mothers, whether we like to admit it or not, shape our lives. As former US president Abraham Lincoln once said: "All that I am, or hope to be, I owe to my angel mother."
I am me because of Grandma.
• Tracee M. Herbaugh is a freelance writer who lives in Boston with her husband and two children.