Just in case you have not seen this. I had a look at the Paternity Index on Scottish Indexes to see if there was an entry which might relate to Margaret Davidson Gillespie. I could not see one but there may be an entry which relates to her brother.
Pursuer Margaret Gillespie 52, Jane Street, Leith
Defender William Brunton, Skinner, 1, Anderson Place, Bonnington Road, Leith
Child born 1890 Year 1891 Court Edinburgh
( I note that the Gillespie family are living at 52 Jane Street in the 1891 census).
William