Thomas Ball likely arrived in Vancouver, by train, in June 1906. I have been able to find him in the 1907 Henderson's City of Vancouver Directory, published in June of that year. His listing reads: Ball, Thomas, plumber, rms, 1016 Westminster Ave. The abbreviation "rms" stands for 'rooms'.
Annie and Granddad would not have likely arrived in Vancouver until mid to late June of that year, due to Granddad's hospital stay in Montreal.
I did check for Thomas in the 1906 directory. However, the publication date for the 1906 edition was given as April and he arrived at Montreal in June, he would not have made it into the directory.