Charles Storer did have a sister Mary, but no brother whose initial was "G." The only brother listed in Storer, Annuals of the Storer Family, p. 49–50, is Elenezer (This note is in error CS did have a younger brother George - RAR 30/8/1991
In AA to JQA, 13 Dec. 1788 (CDF), there is a reference to "George Storer"