Thanks Troth.
You've hit on the confusion I found regarding the marriage and the children.
Because I found three marriages of a Donald and Janet in the area
March 1743 • Dull, Perth, Scotland
Name Donald Monro Gender Male Marriage Date 15 Mar 1743 Marriage Place Dull Scotland, Perth, Spouse Jonet Stewart FHL Film Number 1040063
9 August 1746 • Logerait, Perth, Scotland
Name Donald Monro Gender Male Marriage Date 09 Aug 1746 Marriage Place Logierait, Perth, Scotland Spouse Janet Steuart FHL Film Number 1040125
26 August 1746 • Dull,Perth,Scotland
Name Donald Monro Gender Male Marriage Date 26 Aug 1746 Marriage Place Dull,Perth,Scotland Spouse Jonet Stewart FHL Film Number 1040063
and five children born to a Donald and Janet
Before 5 May1744 – Birth in Dull, Perth, Scotland.
A John Monro was born on or before 5 May 1744 in Dull, Perth, Scotland. He was baptised on the 5 May 1744 in Dull, Perth, Scotland. Father Donald Monro and Mother Jonet Stewart FHL Film Number 1040079.
Before 16 February 1746 – Birth in Weem, Perth, Scotland.
A James Monro was born before 16 February 1746 in Weems, Perth, Scotland. He was baptised on the 16 February, 1746 in Weems, Perth, Scotland. His Father was Donald Monro and Mother Janet Stewart FHL Film Number 1040193
Before 1 November 1747 - Weem, Perth, Scotland
A Charles Monro was born before the 1 November 1747 in Weem, Perth, Scotland. He was baptised on the 1 Nov 1747 in Weem, Perth, Scotland and his Father was Donald Munroe and his Mother was Janet Stewart FHL Film Number 1040193
Before 9 October 1752 – Weem, Perthshire, Scotland.
An Elizabeth Monro was born before the 9 October 1752 in Weem, Perthshire, Scotland. She was baptised on the 9 October 1752 in Weem, Perthshire, Scotland.
Before 28 May 1757 – Aberfeldy, Weem, Perthshire, Scotland.
Robert Monro was born before the 28 May 1757 in Weem, Perthshire, Scotland and he was baptised on the 28 May 1757 at Aberfeldy (Weem) Perthshire, Scotland.
The son Robert is definitely the one in the line I am researching.
Just need to know which marriage was his parents and were all the other children from that marriage.