What is her connection with the Isle of Man?

The 1881 census (transcript free from FamilySearch.org) has:

John KEOUGH Head M Male 38 b.Ireland Coachman
Margaret KEOUGH Wife M Female 38 b.Ireland Coachmans Wife
Source Information:
Dwelling 14 Craven St
Census Place Burnley, Lancashire, England
Family History Library Film 1341993
Public Records Office Reference RG11
Piece / Folio 4147 / 33
Page Number 17

You didn't give enough information to know whether this is the correct couple.

You need to start with what you know - your parents' details (names and dates) - and using the information from their birth and marriage certs then buy the marriage certs for their parents, and then their parents' birth certs, which takes you back to the previous generation so that you can buy their certs, and so on.

Sue