+———James GERVIN (1811/2 County Tyrone, Ireland – 27 Nov 1875 Ottawa, Ontario, Canada)
      |
  +———John GERVIN (6 Jan 1855 Ottawa, Ontario, Canada – 10 Mar 1930 Ottawa, Ontario, Canada)
  |   |        
  |   |   +———William WHITEHEAD (abt 1797 Kent, England – 8 Aug 1844 Ottawa, Ontario, Canada)
  |   |   |
  |   +———Elizabeth WHITEHEAD (17 Mar 1824 St. Marylebone, Middlesex, England – 15 Mar 1911 Ottawa, Ontario, Canada)
  |       |    
  |       +———Mary Jane PARKER (abt 1805 Waterford, Ireland – 6 Jun 1888 Ottawa, Ontario, Canada)
  |    
  Gertrude Elizabeth GERVIN (10 May 1892 Ottawa, Ontario, Canada – 1971)
  |    
  +———Elizabeth WITHERINGTON (1856 – 1917)