James Emery Pryde died 2010 in Dundee aged 93, mother's maiden surname Smith. You will be able to order a copy of the death certificate after New Year when things get back to normal.
James Pryde, mother's surname Smith, was born in Ceres in 1917.
FindaGrave says his parents were John Gatherum Pryde, died 1923 aged 72, and Helen Heggie died 1931 aged 80. In which case his mother was aged 66 when he was born. I think there's a generation missing.
The index to the 1921 census lists in Ceres a family consisting of James, 38; Margaret, 38; Ina, 15; Helen, 11; Ruby, 8; John, 6; James, 4 and Margaret, 1. These match Pryde children with mother Smith: Helen, 1910; Ruby, 1913; John, 1915; James, 1917; Margaret, 1919, all born in Ceres. So it seems that the gravestone is in error.
There are also Pryde children with mother Heggie: Elizabeth, 1875; Helen, 1877; Georgina Joan, 1880; Margaret Jessie, 1885. There's also a James Pryde, no mother's name in index, born 1882, who would exactly fit the 38-year-old in 1921.