Twin girls Kara and Jenna may be 24 years old, but due to their intellectual disabilities, their parents Sue and David Hillier still have to care for them as if they're small children.

At home with the Hilliers

As Jenna sits quietly on the couch and rocks her head back and forth, a loud ruckus is coming from her sister's bedroom.

Kara is stirring.

Suddenly, she begins yelling, thrusting her head from side to side and punching herself in the chest.

She's in the middle of rearranging her furniture, one of her obsessive nightly routines, and if she's unable to do it by herself, she gets frustrated.

Kara's bedroom is filled with magazines - all from the '80s or '90s.

She won't read anything past the year 2000 except for The Australian, which she buys once a week from the local newsagent.

They're all neatly stored in meticulous order.

She has a super memory, so she knows if one is missing.

"If I've taken one, she'll say 'Claudia Schiffer 1992 Cleo'," Sue says.

"All hell will break loose."

"Fly with Qantas to Brisbane, $99. Fly with Qantas to Brisbane, $99," Kara mumbles as she rearranges the magazines and newspapers she has pulled off her shelves.

Sue and David are private people, so welcoming a photographer into their home to capture their family's day is a big deal.

But after many years of hiding their lives away from people, the couple say they want to share the reality of caring for adults with disabilities.

Sue was 16 weeks pregnant when she found out she was having twins.

A few years earlier the nurse had fallen in love with David, a truck driver, who she met when he was one of her patients.

Kara and Jenna are non-identical twins who were both born with an intellectual disability and autism.

There were no signs that either of them had a disability until they were about two years old.

Sue and David started to pick up on signs that their social and verbal development had stunted.

Last time they were tested a few years back, they had the mental capacity of about a six-year-old.

The Hillier family moved to Hamilton in south-west Victoria from Melbourne when the girls were teenagers because it was more inclusive for people with disabilities, and safer.

Once Jenna was picked up in their outer suburban neighbourhood by police, after she ran away naked.

She was going through a phase where she refused to wear clothes.

Kara is higher functioning than Jenna, but they are both obsessive and get anxious with anything outside their usual routine.

"They've both got different traits," David says.

It's Monday - spaghetti bolognaise night.

There's no room for flexibility on that.

There are seven TV and computer screens in the house which the girls insist remain on their assigned channel at all times.

Both of the girls have an obsession with old TV commercials.

Jenna can sit for more than an hour watching old Pizza Hut or Cottee's ads from the 1980s.

Pinned on the fridge is Kara's Christmas and birthday lists for the next two years, detailing very specific items she expects to receive, including people's old VHS mixtapes, so that she can watch the ad breaks.

Sue searches online around the world for them, often forking out exorbitant shipping costs.

'She's 24, and it's like she's a three-year-old'

Morning time is chaotic in the Hillier household.

Before Sue heads off for her shift at the local hospital, she has to shower Jenna, make their breakfast, and get them ready for 'work', their day program at Mulleraterong Centre.

"She's 24, and it's like she's a three-year-old. That's hard," Sue says as she pulls Jenna's top over her head.

"We've seen the other kids in the town go off to university and get jobs and get married. We've still got our 24-year-olds doing the same thing. I'm still showering, packing lunches."

Sue and David hide their own treats because neither of the twins have an appetite off-switch.

Both Kara and Jenna refuse to exercise, so have become overweight as they have got older.

"They just don't want to, and I can't force them to," Sue says.

Even something as simple as getting them to wear a bra is an impossible task.

They don't like the feel of it on their skin, and can't understand its purpose.

When the girls got their period at age 13, neither could cope with it either physically or mentally.

Sue put them on hormones, injected every three months, to stop their menstrual cycle.

"They had one period each, and you'd give them a pad, and Kara would say 'no thank you, no thank you'.

"It was just too messy.

"We call it botox. They accept the injection thinking it's botox."

As their friends are welcoming grandchildren into this world, Sue and David have long ago accepted that they were dealt a very different hand in life.

"I would've liked to have done all the fatherly things, like play football," David says.

"You've got to accept what you've got.

"I look at it as every day is different, and if it didn't work out it should've, well that's life."

'My limit is five years, I'll be 60'

As a trainee nurse Sue spent time at Pleasant Creek 'training centre' in Stawell and at Aradale Asylum in Ararat where, up until not long ago, people like Kara and Jenna were sent and shut off from society.

"You didn't see them other than at Christmas time at the swimming pool," she says.

"Some of them, you only heard about them when they'd died. You didn't even know they'd existed.

"I'd hate to see institutions come back in. It'd just be nice to get the hand."

Caring for two adults with disabilities is starting to take its toll on Sue and David, aged 53 and 55.

The twins are on the Department of Human Services disability support register waiting list.

That would mean they'd live in a residential home with 24-hour care.

But that seems like a long way off yet, and Sue isn't sure how much longer she can cope.

"There is no estimated wait," Sue says.

"David and I might have to do this until we're in our graves.

"I think I've got five years left in me."

Given the transition into full-time care will be traumatic and time-consuming, the couple want to be able to help the girls through the change.

Their biggest fear is that it will be left until it's at crisis point.

"If something happens to me, everything falls in a heap," Sue says.

"We need them settled while we still can."

"I don't think I'm going to live a very long life," David says.

"I picture my father-in-law at 75. Can you imagine Sue or I coping with two adult children? They'll be near 45 and they could still be with us."

Desperate need for disability housing

There's a huge demand for supported accommodation for people with disabilities in Australia.

While many hope the NDIS rollout will bring some relief, the scheme faces a huge shortfall in disability housing.

Sue says the only way she could get the girls in now is to relinquish all rights over their care.

"I know of three boys that were in the girls' class in Melbourne where the parents have actually surrendered their children so that they can get housing, and one of them is still going from accommodation to accommodation," Sue says.

At the moment Kara and Jenna go to respite every Tuesday night, and every now and then they'll stay for a weekend.

It gives Sue and David the chance to recharge so they're able to get up the next day and do it all again.

"We can't just drop everything and go out for dinner with our friends, we can't go on trips, we've never been on a holiday without the girls," Sue says.

"I have no me-time, we have no we-time except for Tuesday night.

"It's depressing, we have times that we get really down about it. And we know we're not alone.

"Sometimes I go away and hide. I escape from the girls' behaviours in books."

When asked what they would do with their lives if they could get their twins into supported housing, the couple are at a bit of a loss.

For many years, their own lives have been on hold.

After pondering on the thought overnight, there are no lavish wishes for the rest of their life - working a little more to set themselves up for retirement, going on road trips to nearby towns, and having a decent night's sleep.

It's simply to be a husband and wife again, Sue says.

"Just to have freedom."