As various BDM events took place in Australia in 1908/9, I assume that they didn't go to Australia until just before these events. I haven't been able to find their arrival into Australia so I can't confirm this. Only Anna's 1920 arrival has turned up (
https://www.familysearch.org/ark:/61903/3:1:3Q9M-CSVT-1SNS-5?i=127&cc=2778600).
PS I'm not sure whether you are interested in the 1875 census, but Soren and Anette were living with Anette's parents:
1875 Norwegian census
Residence: Klokkerstuen Ryggeeiet, Rygge, Østfold, Norway
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Relation to head - Name - Age - Birth place - Occupation
Head - Andreas Nielsen - 50 - Rygge - Husmand Og Arbeidsformand
Wife - Johanne Christofersd - 45 - Rygge
Son in Law - Søren Johannesen - 30 - Vaaler - Tjener Hos Svigerfaderen
Daughter - Annethe Andreasd - 21 - Rygge - Gift Med S Johannesen
Grandson - Johan Sørensen - 1 - Rygge
Son - Nicolai Andreasen - 14 - Rygge
Son - Christian Andreasen - 10 - Rygge
Son - Martinius Andreasen - 7 - Rygge
Son - Thorvald Andreasen - 5 - Rygge
This gives us Søren's birth around 1844/5. I'd read some where that he'd died in SA in 1896, but haven't found any proof. However, a 92y old Soren Johansen dies in VIC AU in 1936 i.e. birth abt 1843/4, so you can understand that I am wondering what the actual truth is …