It's a bittersweet moment in many parents' lives — watching their babies put on their crisp uniform and over-sized backpacks to embark on their new five-day-a-week adventure. But any feeling of vulnerability is tripled for Helen Dimotakis, who never thought she'd see her children grow up.

Eight different cereal boxes are laid out on the kitchen bench, ready for the troops to shout their orders.

Toast orders come in from the lounge-cum-rumpus room; cream cheese with peanut butter for John, honey for Elly and fruit toast for Emmanuel.

Helen tries to get John to eat, while Emmanuel asks again why his letter didn't arrive from the prep teacher.

His brother and sister each got one sent out just after their orientation day, accompanied by some fairy dust to place under their pillow for first-day jitters — but his must still be in transit.

Where does the time go?

All around the country this week, parents are questioning just when their babies happened to grow up.

Many of those "firsts" seem like only yesterday.

The first day of school is a promise of their growing independence.

Water bottles and lunchboxes are prepared, ready for the troops to grab on their way out the door. ( ABC News: Margaret Burin )

For Helen and her husband Ross it brings both amazement and a slight bit of relief.

Triplets are hard work.

"I have a different favourite every day," Helen laughs.

"It all depends on who's behaving the best — You've got to have eyes at the back of your head."

Ross and Helen with John, Elly and Emmanuel on their birthday. ( Supplied )

But the Melbourne mum says her five-year-old boys and girl are also her "miracle".

She was 45 when she fell pregnant through IVF, after a couple of miscarriages and five years of trying for a baby.

A scan at about nine weeks revealed three heartbeats.

"I just laughed but it was more nervous laughter," she says.

The obstetrician raised concerns — for an older mum it was a high-risk pregnancy.

An early surprise

Then at just 21 weeks, four months before the children were due, Helen went into labour.

She was admitted to hospital immediately and told not to get out of bed, not even for a shower.

"They could've been born that day, obviously they wouldn't have survived. It was a matter of just keeping them in as long as possible," she says.

Helen spent over 48 arduous hours waiting to be reunited with her babies. ( Supplied )

The triplets were born at 26 weeks by caesarean.

Helen had to endure two nerve-wracking days until she could see them.

When she finally did, all three of them were just the size of her hand.

Weighing in at only 789 grams, John was the tiniest and wasn't expected to live.

Helen with baby John at only four weeks of age. ( Supplied )

As Helen recovered from her own health issues, their pint-sized bubs spent 97 days in hospital fighting for their survival.

She admits her first year of motherhood was not an enjoyable one.

"I don't remember their baby years, it's all a blur. There was a lot going on," she says.

"I look back at photos and think they were babies and I didn't really get to enjoy them.

"I didn't think I'd get here and now that I'm here it's like 'oh my God'."

The triplets' first Christmas was spent in hospital at three months old. ( Supplied )

From baby steps to big-kid leaps

This week as thousands of Australian children join the education system, any concerns about socialising, bullying, the exorbitant uniform costs or work-life balance are three-fold for Helen.

Not to mention the fear of two of them getting invited to a birthday party and the other being left out.

"I'm a bit nervous. I was more excited, but now I'm getting a bit anxious about how they're going to go and how they're going to settle in," Helen says.

Before she hugs her vulnerable babies tightly and nudges them towards their new reality, five days a week for the next 13 years, Helen takes time to consider how far they've come.

Aside from John having a mild hearing disorder, they don't have any other issues or health complications.

The triplets are ready to embark on their first day of school. ( ABC News: Margaret Burin )

They each have unique personalities, strengths and weaknesses.

Helen's home may be nothing like it was before their arrival, but in between the fighting and chaos, she's grateful for every milestone.

"Every time we visit their obstetrician, he just shakes his head and says 'I can't believe they're here' … He's amazed that they're starting school and gone this far," she says.

"It is a miracle."