How can a mother and daughter just... disappear?

If you disappeared tomorrow, who would look for you?

If you drove away from your life next week, who would wonder where you had gone?

Who would feel your absence keenly enough to question it? To keep questioning it?

Ever since the remains of a tiny girl were found in a dumped suitcase by a South Australian highway in July this year, the question has been: Why was no-one missing her?

How can no-one notice the space a child had left in the world?

Why wasn’t there a little girl’s face on our television every night, flanked by desperate family members determined to find her?

Then, three days ago, came the information that answered one small part of that question. The little girl’s mother was dead.

The one person who would – in a world where everything was in its place – never sleep until you were safe, was gone. Unable to her miss her, and unable to protect her.

We may never know how Karlie Jade Pearce-Stevenson and her little girl Khandalyce came to be more than 1000kms apart, discarded like so much rubbish in bleak, far-flung locations where they would lie undiscovered for years.

But we do know, at least, that there is not a mother somewhere, living with the absence of her child and holding it inside her.

Mothers miss their children. It was Karlie’s mum who was the only person to tell the police that the girls were gone.

No-one had seen 20-year-old Karlie since she and Khandalyce – the two-year-old daughter who had a favourite quilt, a pretty pink dress and a beautiful smile – were seen driving along a desert stretch of the Stuart Highway, south of Coober Pedy in November 2008.

It was a whole year later that Karlie’s mum, who hadn’t seen her daughter since she packed up and left Alice Springs to travel and work, filed a missing person’s report. Only nine days after that report was filed, Karlie’s mum contacted police to say she had heard from someone about her daughter. She was safe, but she didn’t want to talk to her.

Another year later, Karlie’s mum died, taken by illness. And then, there was no one left to look for Karlie and Khandalyce.

Not the little girl’s father. Not her extended family. Not co-workers or health professionals or teachers or friends.

Karlie’s bones were found the year her mother died, but lay unclaimed in a drawer in a Sydney coroner’s court until this week. Despite publicity around a woman’s body found in the infamous Belangalo State Forest, no-one came forward to say it might be her – even with the photofit that has proved eerily accurate, and the distinctive T-shirt that saw the unnamed remains dubbed ‘Angel’.

It seem there’s a world where only mothers hold tight to the ties to their children. And when the mothers are gone, the searching stops. Acceptance seeps in. Karlie was travelling. She was living a life of transience, staying at caravan parks and hotels, finding work when she could.

The last records of little Khandalyce, too young to be in school, were of her vaccinations. Her mother had made sure she got those, it seems, and that was the last time in her short life that the little girl’s existence was recorded, that she came into contact with the system that keeps track of us all, that binds us all to the same time-table: Doctors’ visits and check-ups and daycare enrolments, Medicare claims.

How tightly are you tethered to the world? How easily could you slip off it, without notice?

For many of us, there’s an army of people who would question the space you left – your partner, your parents, your friends, your boss, your colleagues, your teachers, your siblings. Even, in this hyperconnected age, the people who would wonder about a Facebook silence, about why the texts stopped, about why you hadn’t posted for a while.

We are the lucky ones.

It took seven years of absence, and four months of constant media coverage, for anyone to link the little girl in the suitcase to lead to Karlie and Khandalyce.

It was the 1267th phone call to Crimestoppers about the case that finally filled in the space that should have been filled by those two lives. It was from someone who knew that the mother and daughter were missing.

Four calls later, someone called to say they had photographs of Khandalyce with that now infamous quilt.

At last, these two young lives were tethered back to earth.

They had been here. They were gone. Someone had noticed.