1841 census Lonan Baldromma HO107/1464/2
Folio 7 page 8
William Cowin 60 Ag Labourer
Isabella 60
John 29 Ag labourer
James 20 S maker
Edward 15 S maker
Note that although the IGI shows Isabella's maiden name as Cogeen, it shows the mother of John & James ( and a sister, Ellinor, as Cotteen.
The IGI has a Lonan marriage between Isabella Cotteen and William Cowin on November 6 1802.
Either maiden name could be a poor transcription.
To complicate matters, the most likely Isabella in the IGI, christened between 1774 and 1784, is Isabella Codgeen daughter of John Codgeen (no mother's name given).