kahler fitzgearld marrage ireland

I am trying to trace my 3xg grandmother.
Here is what I know. I think her last name was Kahiler
Keleher/Kahlershe married Peter Fitzgerald in Cork Irelandabout 1770 to 1790. I understand that they had about 13 childern all but 0ne were girls and that was the last one WILLIAM .There was a family busniess something to do with fabrick.Peter & this brother Mikewere in charge .
After Peter passed away,William & his wife left the county.They called Mike BLACK MIKE.

Thank you for your help
Florence