I checked the passenger list at LAC for the ship and dates that you gave and came up with the same info as Maureen.
I actually scanned all the pages to see if I could find another person on the pages other than Harry.
Harry R. Root, part of a group of Barnardos Home children, heading to Toronto.
The original passenger list could be either Rook or Root.
Is this the child you are looking for? A home child in a Barnardos group of children.