Not researching family but the following might help.
Unless the family were originally from England, there would be no coat of arms. There are many companies set up to sell irish history of names but not all are correct. Mc could be Scotland originally. There were lots of transplanted Scot and English farmers to Ireland. She should pick the one she likes best and go with that.
Don't worry about spellings so much but consider them all, depended on the person writing down the information.
Spellings are varied:
Griffith Valuation - a census substitute shows spellings as Coley 17, Colley 5, Collie 2, Colly 6, McColly 2 (Dublin City)(1st. resource)www.askaboutireland.ie
Colley is rare: English, related to the Wellesley of the Midland UK also in Irish
O'Colla in Connacht and Rscommon MacCui'lle
Spellings in the 1851 Dublin Census were different again
McAuley, McOley and McCowley
The Tithe Applotments 1823-1837 are also used as an early census (most census were destroyed in Ireland - you can find the 1901/1911 on line.
26 Colley's, 9 Wexford, 1 sligo, 1 Carbury Kildare,
1 Carlow and 7 in Donegal/Tyrone
William, Parish Ardnucher, Tully, Westmeath 1827www.census.nationalarchives.ie
There are 18 Colley's listed for Westmeath
There are 29 Colley's listed in the telephone book for
Have you any idea of when they married as Westmeath baptism and marriage records are on line at www.rootsireland.ie
there is a fee.