Hi Mary
There is a record of the baptism of Martin Kelly in Galway in 1809 in www.rootsireland.ie/
There is a charge to view the full record but it will give you the parish and HOPEFULLY his parents names. I managed to get the parish which was MOYCULLEN RC
http://galwaywest.rootsireland.ie/quis.php?page=0&prevStartQuery=0
I then checked in the Tithe Applotments (free online) which cover 1823-37 and found some Kellys there so if you do purchase the birth record & it has Martin's father's name he might be one of those listed; there are 5 but only 3 have 1st names - 2 James & 1 Pat.
http://titheapplotmentbooks.nationalarchives.ie/search/tab/results.jsp?surname=Kelly&firstname=&county=Galway&parish=Moycullen&townland=&search=Search
I couldn't find the marriage record.
I couldn't find a birth/baptism record for Elizabeth (Collett or Colleth) - hope she didn't have a lisp!
No luck with birth records for the sons either I'm afraid.
There are no Collett/ths in the Tithe Applotments.
Griffiths Valuation 1848-64 free online has 30 Colletts mostly in Tipperary but no Colleths.
No luck on www.irirshgenealogy.ie/ either so I'm not much help on this family Mary.
Col