The Melbourne pair were among the 150 people killed when Germanwings flight 4U9525 crashed into the mountainside in a remote area of the French Alps.
They are believed to be the only Australians killed, although authorities are checking if any dual nationals were on board.
Carol, a registered nurse, midwife and maternal and child health nurse, had a huge heart and always helping other people, according to former colleagues.
Greig was about to embark on a new journey, planning to teach English in France, the family said.
Enjoying a few weeks holiday together at the start of Greig's European stay, the family said they were in "deep disbelief" at news of their deaths.
"They were both extraordinary people who were loved by many, who they loved in return," the family said on Wednesday.
The tragedy comes within 12 months of the Malaysia Airlines MH370 and MH17 disasters.
Thirty-eight Australians were killed in the MH17 crash in eastern Ukraine last July. Sixteen of the victims were from Victoria.
Flight MH370 disappeared in March last year with 239 people, including six Australians, while flying from Kuala Lumpur to Beijing.
