Hello,
I take it that the 8 children you refer to - sourced from the IGI - are below. (children to Isabella Keith and Andrew Mitchell).
Also from the IGI (
www.familysearch.org), you have 2 choices of marriages - assuming the marriage took place before the first child. I did a 5 year search either side of 1825 and came up with 2 possibilities.
1. Andrew Mitchell m Isobel Keith on 13 Oct 1822 in Forgue , Aberdeen (shire) , Scotland.
2. Andrew Mitchell m Isabell Keith on 12 Oct 1822, Auchterless, Aberdeen (shire) , Scotland.
GEORGE MITCHELL Christening: 25 OCT 1835 Rothiemay, Banff, Scotland
CHARLES MITCHELL Christening: 24 JAN 1833 Rothiemay, Banff, Scotland
JOHN MITCHELL Christening: 14 MAY 1829 Rothiemay, Banff, Scotland
PETER MITCHEL Christening: 01 JAN 1832 Rothiemay, Banff, Scotland
JAMES MITCHEL Christening: 08 MAY 1825 Rothiemay, Banff, Scotland
WILLIAM MITCHEL Christening: 25 MAR 1827 Rothiemay, Banff, Scotland
ANDREN MITCHEL Christening: 08 DEC 1822 Rothiemay, Banff, Scotland
ROBERT MITCHELL Gender: Male Birth: 05 OCT 1838 Rothiemay, Banff,
Scotland.
Andrew died on Eighteenth September 1864 - aged 63. I tried searching on Scotlands People (
www.scotlandspeople.gov.uk)| for his birth. There were 39 births with the name between the dates below and no luck.
(You searched for: Surname: "Mitchell"; Use Soundex: On; Forename: "Andrew*"; Sex: "Male"; Date From: 01 January 1798; Date To: 31 December 1803;)
I searched for Martha Pantons birth from 01 Jan 1779 to 31 Dec 1783
And came up with:
Martha Panton -b. 16/11/1779 to John Panton and Agnes King. Parish: West Kilbride, County : Ayr. GROS Data: 620/0010
So, now over to you and others to see if you can get any further forward. All the best.
Regards, Steve :O)