aghadowey & dathai. Looks likely that Marguerite may have used her mothers maiden name at some stage and lived in 430 Parliament and friend Ellen Shepard lived in 420 Parliament prior to Ellen's marriage to George Pymm. Both buildings can be viewed on Google Earth at street level. I am more and more convinced that Marguerite and probably Ellen Shepard were Home Children. But I have not found them in the records I have searched.
I have found a Margaret Craig in the 1911 Canadian census, born 1888 in Scotland. This person was a single lodger in a large family of Scot's (Stephens), so being listed as being born in Scotland would be logical error. But even if this is Marguerite, it is difficult to see this getting us closer to determining where she came from in Ireland. Link as follows:
https://familysearch.org/ark:/61903/1:1:27X3-5TXI have spent much time looking at shipping records from Ireland to Canada and some Canadian sites listing children in care, all to no avail.
Thank you for your efforts. Looking more and more unlikely that the origin of Marguerite Cecilia Craig will remain a mystery.