How old was O. Henry in The Third Ingredient?

Mildred ManningMildred Manning was 26 in The Third Ingredient as 'Hetty'.

Birthday: Wed, Aug 13 1890 –
Fri, Feb 22 1963

Alice MannAlice Mann was 17 in The Third Ingredient as 'Cecille'.

Birthday: Tue, Oct 10 1899 –
Sun, Mar 02 1986

J. Frank GlendonJ. Frank Glendon was 30 in The Third Ingredient as 'Man'.

Birthday: Sat, Oct 23 1886 –
Wed, Mar 17 1937

Thomas R. MillsThomas R. Mills was 38 in The Third Ingredient as 'Director'

Birthday: Thu, Jun 27 1878 –
Sun, Nov 29 1953

O. HenryO. Henry would have been no older than 47 in The Third Ingredient as 'Story'

Birthday: Thu, Sep 11 1862 –
Sun, Jun 05 1910