Hi, I think perhaps the mail may have travelled by ship?
If the letter was postmarked Vancouver - it would have been sent from here.Perhaps by train - to the East Coast -
Was there an announcement published re the second marriage of the son - {when?] it may have mentioned his mother attending.
Are there other records available to you - re the marriage of the son. Church Records etc -which may show a clearer version of the surname.
Did she return to Canada? after the marriage of her son?
It is odd that the children? have no information about their mother ? -or are they no longer living ?
Alberta is difficult to search re Vital Statistics - Birth,Marriage,Death.
All is considered Private. Informatin may be available to some [family] as well upon proof that the person is deceased.
The Vital Statistics Registry office may search a few years either side of a given date. The cost is $40 Cndn.
Alberta GenWeb Local History Book Project
http://www.rootsweb.ancestry.com/~canab/lookups.htmlThe following are the only names that come close.
BROTHERTON, Don; Akokiniskway; Mountainview
BROTHERWOOD,John,Esther (Kemble);Under Eight Flags; Warner.
BROTHERWOOD,John,Esther (Kemble); Wagons to Wings; Warner.
Cheers, Stella