Name: Anthonius Koolen
Gender: Male
Birth Date: abt 1902
Departure Place: Amsterdam, Netherlands
Arrival Date: 22 Jun 1951
Arrival Place: Fremantle, Western Australia, Australia
Age on Arrival: 49
Vessel: Groote Beer
According to the passenger list, he was accompanied by Johanna Koolen-Strik
Name Johanna Koolen-Strik
Gender Female
Birth Date 1907
Departure Place Amsterdam, Netherlands
Arrival Date 22 Jun 1951
Arrival Place Fremantle, Western Australia, Australia
Age on Arrival 44
Vessel Groote Beer
Also on the passenger list are :
Franciscus A M Koolen Male 1941 Amsterdam, Netherlands 22 Jun1951 Fremantle, Western Australia, Australia 10 Groote Beer
Johanna M A Koolen Female 1943 Amsterdam, Netherlands 22 Jun1951 Fremantle, Western Australia, Australia 8 Groote Beer
Anthonius H M Koolen Male 1945 Amsterdam, Netherlands 22 Jun1951 Fremantle, Western Australia, Australia 6 Groote Beer
I'm thinking those are the children - and the earlier mentioned Johanna Maria Koolen-Van Doorn, who died in Moe in 1984, was a daughter-in-law. Maybe.