Madeline Holtznagel attends Australian Fashion Week with her model sister Simone

Madeline Holtznagel chose a night out with her sister on Monday.

The model attended Australian Fashion Week at Sydney’s Carriageworks with her 28-year-old brother, Simone Holtznagel.

Attracting attention with an oversized dress, 26-year-old Madeline preferred a large striped blazer in dark navy blue with nothing underneath.

She paired it with the same designer’s wide-leg trousers and a pair of black heeled sandals.

Confused, she carried a bronze purse with a knotted leather handle in shades of brown and orange.

Madeline put her blonde hair in a neat ponytail and put on a glamorous make-up with a smoky eye and matte nude lipstick.

Cool: Standing out in a loose-fitting dress, Madeline opted for a large striped blazer in dark navy with nothing underneath.

One look: The same designer paired wide-leg trousers with a pair of black heeled sandals and a brown bag.

Meanwhile, Simone opted for a slate gray dress with a deep V-neck that shows off a loose bust in the front.

He posed outside in a coat, black trench coat emerging from below.

The model opted for dramatic make-up, complete with peach blush and dark pink lipstick.

Details: Simone opted instead for a slate gray dress with a deep V-neck at the front.

Rainy day: Posed outside in a jacket, black trench coat revealed from below

Make-up: The model opted for a dramatic make-up complete with peach blush and deep pink lipstick.

Simone wore her blonde hair in a ’60s updo and added a pair of natural pearl earrings.

She completed the look with a dark brown handbag and strappy nude heels.

Madeline attended the event without her billionaire boyfriend Baron, 49-year-old Justin Hemmes.

Party time: She was joined by boyfriend Ksenia Lukich (right)

On fire: Simone wore her blonde hair in a ’60s updo and added a pair of natural pearl earrings

The Final Touch: She completed the look with a dark brown clutch and strappy high nude heels.

It’s not known exactly how long Justin and Madeline have been together, but he has recently hinted that their relationship has lasted longer than many people expected.

Speaking to the Sydney Morning Herald in October, Madeline said they had met for two years before news about their relationship surfaced early last year.

“We’ve known each other for two years and met while modeling in Singapore,” she said at the time.

Girls girls girls: Simone spoke to Imogen Anthony (right)

Laughs: The group shared a lively chuckle as they talked outside the room.

Downpour: Simone carried an umbrella to protect herself from the rain

The couple was rather timid throughout their relationship, but it is believed that they lived together.

Last month, the billionaire and baron baron model hosted the Silver Party charity event at Hemmes’ The Hermitage estate in Sydney’s Vaucluse.

They have also been exchanging tributes on social media from time to time since they went public.

Leisure: Madeline attended the event without her billionaire boyfriend and baron Justin Hemmes (center). Photographed with a friend