Question

Who is the wife of Archibald, 7th Earl of Argyll, Campbell?

Answer 1

According to The Complete Peerage of England, Scotland, Ireland, Great Britain, and the United Kingdom, by George Edward Cokayne, Vol. I--he married, firstly, Agnes Douglas, daughter of Sir William Douglas, 7th Earl of Morton and Agnes Leslie. He married, secondly, Anne Cornwallis, daughter of Sir William Cornwallis and Lucy Neville.

See: http://our-royal-titled-noble-and-commoner-ancestors.com/p2216.htm#i66600

Profile: http://www.wikitree.com/wiki/Campbell-10875

Answer 2

You can find a biography of Archibald Campbell, 7th Earl of Argyll, in the  Dictionary of National Biography.  It says that he married twice: first, in 1592, to Anne Douglas, 5th daughter of William, 1st Earl of Morton, of the house of Lochleven, and had 1 son and 4 daughters.  He married second wife on 10 Nov 1610. She was Anne, daughter of Sir William Cornwallis of Brome.  Her influence caused him to convert to Catholicism.  They had 1 son and 1 daughter.