Mary Devitt or Davitt

I am looking for family of my 3rd gr grandmother Mary Devitt or Davitt, probably born around 1800 or a little earlier.  Known facts: She was from Co. Leitrim.  She married (unknown) Beirne.  They had children Thomas, James, Catherine, Owen, Ann.  All but Thomas left for the US during the famine.  Thomas ended up in Cornacranahey, Kiltohert Parish, Drumshambo, Co. Leitrim.  He still has Beirne decendents there.

Our family bible says Mary's name was Davitt but I know it could have just been pronounced that way in in fact been Devitt.  I have decided to post on this parish site as I know there are a number of Devitts and perhaps Davitts.  I have a 2007 calander from Drumkeeran that shows a number of people with the surname Devitt.  Any help anyone could give would be helpful.

I have been to Co. Leitrim but not to that area, I stayed down in the Carrick-on-Shannon area.  I have looked at Griffiths Valuation but not knowing Beirne's first name and not knowing where Mary lived as a child it is difficult, along with not having many remaining records!!   Just throwing it out there.  I did find my relations in Cornacranahey by this method so homefully I can be 2/2!  Mary