Given what we've already found, my theory is thus: the photo you have from 1965 is likely that of Clara, mother to Emma -- who would have been Edward's grandmother (and matches the info you had originally about the relationship, if not the name).In 1965, Emma would only have been 60 years old (born 1905), so not so very old.Clara would likely have been in her 80s.
I found Clara's marriage in Farnham, Quebec (which matches the info on Emma's death certificate):
(translated from the original French)
22 October 1900:
Nisier (or Nigier) Martel, son of age of Pierre Martel & Elizabeth Lafontaine, of the parish of Brigide(?), married Clara Menard, of this parish, minor daughter (ie, less than 18), of Benjamin Menard & Anna Guillette.
Baptism for Emma (Maria Emma Evangeline Martel):
Baptised 1 April 1905, born yesterday, of the legitimate marriage of Nizier Martel & Clara Menard.
In 1908, I found Nizier, aged 35, a carpenter, crossing from Canada to the US, from St. Boniface, Manitoba (naming his wife, Clara, as his contact in Canada), bound for North Dakota.The family must have moved from Quebec to Manitoba and perhaps that is where Emma married Arthur.
In 1943, I found Clara (Marie Claire Menard Martel) crossing at Detroit, born 20 June 1882 in Farnham, Quebec. No other info on the card.