Hugely impressed with this mass of detailed information, and extremely grateful!
My next lines of enquiry -
(1) Was Ada still working for the Lacks family in Kingston (Wimbledon?) Surrey in the 1901 census? Meanwhile AJB was in Wimbledon in 1891 and Wandsworth in 1901
(2) Track down Alfred John's passage to Canada, thought to be 1902, Liverpool to Montreal. How do I pinpoint his entry on the Canadian Passenger List with only name, year, and ports of departure and arrival?
(3) Follow up the movements of the Montreal children (Russell, Beatrice, Florence, Idah, Stanley, Clarence) after 1921. The 1931 census is not available until 2023. What is the best line of approach?