Hi,
It's just a guess. I looked at the IGI for Perthshire between 1748 and 1761, and this was the only one with a reasonable date where both parents matched her children's names. But the IGI isn't a complete record, and she may not have called her kids after her parents. Here are all the results;
Katharine Clark 10 January 1748 KILLIN, PERTH, SCOTLAND Donald Clark/Katharine Stuart
Cathr. Clerk 1 April 1748/10 April 1748 CULROSS, PERTH, SCOTLAND George Clerk/Margt. Ronald
Kathrine Clark 15 April 1750/22 April 1750 PERTH, PERTH, SCOTLAND John Clark/Janet Red
Katharine Clark 3 September 1754 KILLIN, PERTH, SCOTLAND Donald Clark/Janet Mcilglass
Katharine Clerk 24 April 1755 BALQUHIDDER, PERTH, SCOTLAND Finlay Clerk/Nclaren
Katharine Clark 27 September 1756 KILLIN, PERTH, SCOTLAND Donald Clark/Janet Mciver
Catharine Clark 9 October 1756/13 October 1756 CALLANDER, PERTH, SCOTLAND Donald Clark/Janet Mcfarlane
Cathrine Clerk 5 November 1757/1 December 1757 KENMORE, PERTH, SCOTLAND Finlay Clerk/Cathrine Cameron
Cathrine Clerk 2 May 1758/9 May 1758 KENMORE, PERTH, SCOTLAND Donald Clerk/Cathrine Mc Laren
John.