Fatima Elomar, 31, was intercepted at Sydney Airport in May last year as she tried to board an international flight.
Cash, camouflage gear and medical supplies were found in her luggage.
In a brief court appearance, she pleaded guilty to supporting incursions into a foreign state with the intention of engaging in hostile activities.
Mohamed Elomar travelled to Syria and then Iraq in 2013 to fight with so-called Islamic State (IS).
Court documents reportedly detail text messages between the couple in which Ms Elomar begs her husband to return home for medical treatment after being shot.
Mr Elomar reportedly told his wife to prepare the children's passports so they could be together in Raqqa, Syria.
Mr Elomar, and fellow Australian Khaled Sharrouf came to public attention last year after they posted pictures of themselves posing with severed heads to social media.
One of those images showed Sharrouf's seven-year-old son holding up the severed head of a Syrian soldier.
It is believed Elomar died in June during an air strike on a convoy of vehicles near IS's self-declared capital of Raqqa.
The Australian government estimated in September that around 120 Australians were currently in Iraq and Syria to support IS and other terror groups.

5 January 2016 Last updated at 10:38 GMT
It is not known how the swan got trapped on the rooftop of Agatha's Boutique but it could not fly off as it did not have enough space to take enough of a run up.
A spokeswoman for the RSPCA said: "Happily we were able to rescue this swan and release it back into the wild just a short distance away."
Staff at nearby soundLINCS managed to record the successful rescue.

Sergeant Peter Rayner, 34, from Bradford, West Yorkshire, of 2nd Battalion The Duke of Lancaster's Regiment, was killed on Friday.
The soldier was carrying out a patrol in the Nahr-e Saraj area of Helmand Province.
The number of British military personnel killed in operations in Afghanistan since 2001 is now 340.
Sgt Rayner's wife Wendy led tributes to the "fantastic" and "loving" husband and father to son, Derek.
"He loved his job and doing something which he believed in.
"He will be sincerely missed by all who knew him," she said.
Sgt Rayner was born into a military family, and his parents Peter and Bernadette said their son was "always full of energy and was someone who enjoyed life to the full".
"As a soldier he loved his job and was totally committed to the Army, as well as his family and friends.
"As a son and brother, he was a fun-loving and caring person of whom we are all very proud.
"We loved him so dearly and will miss him with all our hearts."
The MoD said Sgt Rayner, who had also served in Bosnia and Iraq, would be "sorely missed" and remembered for his "pre-eminence as a Javelin Commander, for his forthright manner and for his huge personality".
Sgt Rayner's bravery and courage had attracted much praise in Afghanistan, it said.
Lieutenant Colonel Robbie Boyd, Commanding Officer 2nd Battalion, The Duke of Lancaster's Regiment, said: "He was honest, loyal and always vocal.
"A true Lion of England and a man of high morals, guts and integrity.
"A man who cared not just for the morale of his soldiers, but in how that morale was created.
"A man with great spirit and forthrightness, who was as true as his aim was with a Javelin Missile."
Major Paul Tingey, Officer Commanding Arnhem Company, 2nd Battalion, The Duke of Lancaster's Regiment, said Sgt Rayner left a "lasting impression" on people.
"He spoke his mind and always had the best interests of his men at heart.
"He was someone that you could rely on to tell you exactly what he thought. I always welcomed his words of advice.
"I will remember Skippy as a devoted family man, a fanatical mountain biker and one of the best commanders that I have had the privilege to work with," he said.
The wife of one of Australia's most notorious extremists, Mohamed Elomar, has pleaded guilty to supporting overseas terrorism.
[NEXT_CONCEPT]
An RSPCA worker has rescued an adult male swan from the roof of a building in the centre of Lincoln.
[NEXT_CONCEPT]
A British soldier killed in an explosion in southern Afghanistan has been named by the Ministry of Defence.