Having checked the full image for this death record I see that the deceased was 75 in 1858 so born around 1783.
Father is given as John McPherson, farmer. As shown on snippet mother's maiden name was Gordon. Maybe trying to trace the marriage of John and his wife may help with her name.
The only marriage I can find on the Church of Scotland Registers is 26 May 1785 at Kirkmichael and Tomintoul. John's spouse is given as Pen.Gordon. I haven't looked at the image for this.
The Roman Catholic Church comes up with date of 26 June 1785 and the name Pinny Gordon. Again not looked at the image.