An Australian woman who lost her brother in the disappearance of Malaysia Airlines Flight 370 has learned that her stepdaughter was on the Malaysia Airlines flight shot down over Ukraine.

Kaylene Mann's brother Rod Burrows and sister-in-law Mary Burrows were on Flight 370 when it vanished in March. On Friday, she found out that her stepdaughter, Maree Rizk, was killed on board Flight 17 when it crashed in Ukraine.

Ms Mann's other brother Greg Burrows said news of the second tragedy to hit the family has "ripped our guts again".

Ms Rizk and her husband Albert were returning home to Melbourne from a four-week European holiday.

Mr Burrows said his family was struggling to understand how they could be struck by such horrible luck on two separate occasions with the same airline.

"She just lost a brother and now a stepdaughter, so..." he said of his sister, his voice trailing off.

Tributes were paid by Phil Lithgow, president of Sunbury Football Club, with which the family was heavily involved.

Mr Rizk, an estate agent, was a member of the club's committee, his wife was a volunteer in the canteen and their son James plays on the club's team.

"They were very lovely people," Mr Lithgow said. "You wouldn't hear a bad word about them - very generous with their time in the community, very community-minded, and just really very entertaining people to be with."

The club members plan to wear black armbands and observe a minute of silence to honor the Rizks at their game tomorrow, Mr Lithgow said.

Despite the twin tragedies, Mr Burrows said he holds nothing against Malaysia Airlines.

"Nobody could predict they were going to get shot down," he said. "That was out of their hands."