Another name for Margaret was SYMER, Margaret.
Margaret married Thomas FORBES, son of William FORBES 4th of Barnes and Agnes ERSKYNE. (Thomas FORBES was born about 1618.)
"Thomas Forbes of Awhorthies Married Simer who bear to him one daughter married to Kinadie Straked and had no more issue."
1 Internet Site, http://digital.nls.uk/genealogical-collections-concerning-families/pageturner.cfm?id=74538860.
Cemetery Records, Headstone St Patrick's Cemetery New Stevenston Lanarkshire.