Story highlights It's an act of God that her father got hepatitis, says woman who canceled her family's flight

Her brother forget to check emails, and it made their family miss the plane, another says

Seven members of the two families who did not board QZ8501 are children

Family members break down into tears when they hear the news of the missing plane

Some may call it serendipity, others divine intervention. Either way, circumstances prevented two families from boarding doomed AirAsia Flight QZ8501.

In one case, it was missed emails. In another, an illness in the family. As a result, 15 people -- seven of them children -- are alive and well.

'Truly a miracle'

It was no stroke of luck but an act of God that her father caught hepatitis, said Inge Goreti Ferdiningsih, because it made her family cancel their tickets on the AirAsia flight a day before it took off.

"We are extremely grateful, and God is really great," she said. "I believe that God is saving and protecting us, and this is truly a miracle."

Inge Goreti booked the family vacation nine months earlier. Her father wasn't booked on the trip, and her younger sister was staying by his side.

Inge Goreti Ferdiningsih with her family.

So, Inge Goreti could still have gone, with her husband and three children.

'Feeling in my heart'

Inge Goreti's father got hepatitis.

The bags stood packed and ready, and the family was full of anticipation for the Singapore vacation. Christopher 10, Nadine, 7, and Felix, 5, were psyched about taking a local ship cruise, splashing at a water park and watching animals perform at Sea World.

But then Inge Goreti's sister called from a hospital, where she had taken their father after he complained of stomach pains. The diagnosis: hepatitis.

Doomed flight booked for the whole family.

The news tugged at her. "I had this feeling in my heart that I wanted to be with my dad," Inge Goreti said.

So, she called off the trip Saturday, a day before the flight.

Christopher had a hard time accepting it. He was so looking forward to the trip and became very upset, she said.

'We were late'

An aversion to phone messages may have spared another family.

Christianawati was going to ring in the New Year in Singapore with her family and her brother's family, she told a French news agency. Ten were traveling in all.

But her brother forgot to check messages from AirAsia telling them that the flight was leaving two hours before the original departure time.

"They emailed and called us on December 15 and 16 to inform us, but we missed those calls," Christianawati, who goes by one name, told Agence France-Presse.

"So we arrived at the airport to check in for the 7:30 a.m. flight but were told our flights had been rescheduled to 5:30 a.m., and we were late. Of course we were angry," she said.

Some family members pulled up in their car just in time to see the last passengers whisk past them into the boarding lounge, The Sydney Morning Herald reported

But Christianawati's family was traveling in two cars, and one was lagging behind. They just missed the flight.

Then they heard the news.

"Maybe it is all God's plan that my family and I were not on the flight," Christianawati said. "It was a blessing in disguise."

'Broke down and cried'

Early Sunday, at Inge Goreti's home, the phone rang -- a few times.

"We received calls from relatives regarding the plane that lost contact," Inge Goreti said. "We all broke down and cried."

Sunday evening, the family went to church to give thanks.

But mixed with Inge Goreti's tears of relief have been tears of sadness. She recognized names on Flight QZ8501's passenger manifest, she said.

Friends and colleagues were on board.