Creeping down the hallway, I couldn't help but giggle.
"Shh!" My best friend, Kerryn, hissed, gripping my hand and leading me outside into the fresh night air.
We were 16 and had snuck out of my home during a sleep-over.
In the city, we talked our way into clubs to dance the night away.
There was no doubt about it, Kerryn was my partner in crime.
She had been since we'd first met at 13.
She'd seemed so shy at first.
I'd never have guessed she could be as wild as me.
From then on, we were inseparable.
Even my mum thought of her as one of her own.
When Kerryn fell pregnant at 18 and had a little girl, Steffanie, she was soon a single mum and moved to just around the corner from us to be close.
Determined to make a great life for her daughter, she joined the army and travelled around the country.
We kept in contact through weekly letters.
Miss you so much xx, I always wrote at the bottom.
Then at 21, I was struck down with a kidney infection.
Tests revealed I had a hereditary disease that caused cysts to grow on my kidneys.
It meant they would gradually stop functioning.
"But…" I mumbled in disbelief.
No-one in the family had ever mentioned this to me before.
"You've got it from me," Mum said sadly, explaining how she'd kept it secret so she didn't worry me about something that might never happen.
I thought back to when I was a girl and Mum had been in hospital with a bad kidney.
"It's nothing," she'd reassured me at the time, insisting it was a one-off.
She'd been managing with the condition ever since then.
I called Kerryn to tell her and after the initial shock, she found ways to cheer me up, as only she knew how.
I'd need a transplant at some point, but all I could do for now was live as healthy a life as possible.
"It probably won't be until you're 60," the doctor said.
So for the next few years I had a ball working in hotels in a few different countries.
When I returned to Australia, Kerryn was still busy in the army.
Then, when I was 44, I went for a routine mammogram and the doctor found a lump in my left breast.
It was cancerous and I'd need to have a mastectomy.
Rushing home, I called Kerryn straightaway.
"I'm coming over right now," she said sternly.
By then, she was a mum of three kids, but as usual she moved mountains to be there for me.
Wrapping me in a hug as I sobbed, she promised she'd be with me every step of the way.
I asked the surgeon to take both breasts as a precaution. I couldn't risk the cancer spreading to my right breast, too, as the medication to kill off the cancer cells would delay me from receiving a kidney transplant by five years.
That was too much of a gamble.
The operation was a success, but without my breasts, I felt like less of a woman.
"What guy will want a woman with no boobs?" I fretted to Kerryn.
"Honey, if he's got that attitude, you really don't want him!" she scoffed.
Two years later, I found myself constantly exhausted.
My specialist said my kidneys were functioning at 17 per cent.
"You need a transplant right away," he said.
But finding a donor who was a match could take years.
I was in serious danger.
"I'll give you mine," Kerryn said when I told her.
It was so typical of her to offer, but I couldn't possibly accept.
She had three kids to care for.
What if something happened during the procedure?
I'd never live with myself.
"You're so kind, but..."
"But nothing," she interrupted. "I just know I'll be a match."
It took 12 agonising months to confirm it, but miraculously her kidney was compatible!
"Told you!" she joked.
I felt riddled with guilt as she was wheeled into surgery.
My best friend was putting her life on the line for me.
Thankfully, the procedure went smoothly for us both and for the next year, Kerryn came over to do the cooking and cleaning while I recovered.
As if she hadn't already done enough!
Now my health's better than ever and I'm fun-loving and independent again.
But one thing's never changed, and that's my friendship with Kerryn.
She saved my life. I might have her kidney, but she'll always have a piece of my heart.