Hi Niknak13
I have found another child for your couple through a birth record on Pilot IGI:
John Mathew
Birth Date: 26 Oct 1822
Birthplace: MARKINCH,FIFE,SCOTLAND
Father's Name: Thomas Mathew
Mother's Name: Christian Tod
Collection: Scotland Births and Baptisms, 1564-1950
I took an interest in this post because I have some Matthew research and I know of the family who I show below, where the John Matthew, also from Markinch, married an Ann Christie in 1835.  They moved to Ferry Port on Craig and settled there for many years:
1851 Scotland census in Spean Hill, Ferry Port On Craig, Fife, Scotland
 John Matthews born in Markinch, Fifeshire, Head, aged 66, occupation "Gardner"
 Ann Matthews  Dysart, Fifeshire, Wife, 46, Gardners Wife 
 Elizabeth Matthews  Ferry Port On Craig, Daughter, 14, Scholar
 David Matthews  Ferry Port On Craig, Son, 12, Scholar (a person with this name was witness at my John's grandson's James's marriage in 1898).
 Robert Matthews  Ferry Port On Craig, Son, 10, Scholar
 Edward Matthews  Ferry Port On Craig, Son, 8, Scholar
 Andrew Matthews  Ferry Port On Craig, Fifeshire, Son, 6, Scholar
 Thomas Matthews abt 1847  Ferry Port On Craig, Son, 4