The Jack Pine

My grandmother was an oil painter. Her favourite subject was trees. The beloved Canadian painter Tom Thomson painted The Jack Pine in 1916. When, in 1918, the National Gallery purchased it, 'The Jack Pine' became quite famous within Canada. Reproductions hung in Canadian schools.

I wonder if my grandmother was influenced by Tom Thomson's painting when she began this painting? When was it painted, I wonder? If grandma did this painting of a Jack Pine when my mother was eleven, the date would be 1940. If it was painted when my mother was 19 (and this is more likely)the date would be 1948.

It is signed E J in the lower right. (for Ethel Jane)
The artist (my grandmother) was 56 in 1948. A significant age.