www.collectionscanada.gc.ca/databases/index-e.htmlyou can check the passenger lists for Catherine, Thomas, and Anton at this site.
Anton Passens
age 21, nationality HOL
1927/04/08 Halifax
NIEUW Amsterdam - Holland American
1927 Vol 6, page 48, T-14809
click on the above webpage and then go to Immigration Records 1925-1935
under Search, put in Passens (surname)
this will bring up Anton Passens on a new page
you will see How to consult a Record or Order a Copy, click on that and then scroll down until you see Microform Digitization.
click on that and then on Passenger Lists Halifax, go to reel T-14809. there are several volumes on each reel so you can't just go by the page number listed above. He is on page 251.
Anton Passens
Rotterdam, Holland
destination - CNR Montreal
gives his fathers name
Catherine's arrival was listed as 1926, she is age 21. You can access the passenger lists for Catherine and Thomas in the same way as for Anton.