Hello
Welcome to Rootschat. As I'm sure you're aware - you're searching in McLaren country.
A cursory search of the IGI -
www.familysearch.org brings up 10 children for Archibald amd Margaret:
1. JOHN MCLAREN -Ch: 29 APR 1798 Balquhidder, Perth, Scotland
2. ROBERT MCLAREN - Ch: 22 DEC 1799 Balquhidder, Perth, Scotland
3. JANET MCLAREN - Ch: 10 OCT 1802 Balquhidder, Perth, Scotland
4, ARCHIBALD MCLAREN - Ch: 04 NOV 1804 Balquhidder, Perth, Scotland
5. JANET MCLAREN - Ch: 12 MAY 1807 Balquhidder, Perth, Scotland
6. DUNCAN MCLAREN - Ch 10 SEP 1809 Balquhidder, Perth, Scotland
7. MARGRET MCLAREN - Ch: 17 JUL 1812 Balquhidder, Perth, Scotland
8. MARGARET MCLAREN - Ch: 27 OCT 1814 Balquhidder, Perth, Scotland
9. WILLIAM MCLAREN - Ch: 20 SEP 1818 Balquhidder, Perth, Scotland
10. DONALD MCLAREN - Ch: 28 JAN 1821 Balquhidder, Perth, Scotland
I'm not related - my wife was born in Killin though. What information are you looking for?
Regards, Steve :O)