In chapter 7, a sense of fatalism is created when Mike decides to stay overnight in the bush. This creates a sense of fatalism because the bush is very dangerous especially during the night, where everything is unexpected and unknown.
“It might even end, if it ever did end, in a sudden unexpected finding that had nothing to do with all this purposeful seeking.”

This example is a bit vague and general. Have another go !

The narrator foreshadows Sara’s death through Irma’s comments; "Sara reminds me of the little deer Papa brought home once. The same big frightened eyes. I looked after it for weeks but Mama said it would never survive in captivity.” “And did it?” they asked. “It died. Mama always said it was doomed.”’
As Irma compares Sara to her deer that died even after weeks of nurturing (like Miranda looked after Sara), she implies a sense of fatalism upon the orphans life.

This is a fantastic example-Irma's comparison. The word 'doomed' describes Sara's predicament from the very beginning.
Well chosen !

The setting of the story suggests a sense of fatalism. On the day of the Picnic, the morning is described as practically perfect.
‘Everyone agreed that the day was just right for the picnic to Hanging Rock, a shimmering summer morning warm and still…’
In the above quote, the narrator describes a perfect setting. Everything about the morning of the Picnic is perfectly organised and going to plan. As we know, life is not perfect, and the eerie perfection that the author creates makes the reader wary.

...this is more or less the same example I used to introduce this idea...maybe you can find some other comment from the omniscient narrator. This type of narration helps in creating the sense of fatalism.

Nearing the End of chapter two the author gives us part of Michaels interior monologue where he reminds himself that ‘he was in Australia now: Australia, where anything might happen.’ This creates a sense of foreboding that something will go uncontrollably wrong. This same sense fatalism is shown when the three adults are talking about the peculiarities of their watches stopping all on twelve. The author writes how
‘Mr hussy was reduced to looking knowingly at the shadow of hanging rock which ever since luncheon had been creeping down towards the picnic grounds on the flat’
the image of the shadows of the hanging rock gradually creeping down to the group of girls and adults shows the idea of the mind capturing, mysteriousness of the rock and its surroundings. It makes the rock sound as though its shadows are going to wrap around the congregation and steal them away.

Michael's opinion on Australia is a very good example and it was a view common to many 19th century settlers...that sense of unease and fear of the outback/bush. The personification of the shadow of the rock is very sinister.

The motif of ‘time stopping’ is crucial to the idea of fatalism. When three of the characters watches stop at Hanging Rock it symbolizes the fact that time has run out for some of the characters.

In chapter 1, the sense of fatalism is portrayed through the use of foreshadowing. The quote, “Marion said, “I only wish someone had sent me a map of the Hanging Rock for a Valentine, I could have taken it to the picnic…”, suggests that the girls might get lost at the Hanging Rock picnic grounds.