missing children between 1820-1835ish

[fiona g]

Trying to trace any children born to William Burnside and Isabel/isabella Hood between 1820 and 1835,most likely anywhere in East Lothian.I have 3 children born to them
                                                         William b1817 Gifford
                                                          James b 1819 Garvald
                                                          John   b1830ish Bolton
William and James where easy to find John I only found though his death record recorded with the surname Burns.I feel there could be more children of William and Isabel since there is 11/12years gap between James and John.Any help or advise welcome.

N.B.  There is another William and Isabel (Laidlaw)in the same era with children Alexander James and Helen,although I am sure they will be connected I havent researched them yet.

Fiona