Methodism took much longer in Ireland to become established as a separate denomination than was the case in England and elsewhere. Prior to the 1830s most Methodists in Ireland would have used the Church of Ireland for baptisms & marriages, and in some cases it was the 1870s before they used their own Ministers. So, prior to the 1830s, your families probably used Billy Church of Ireland. Unfortunately that church's early records were lost in the 1922 fire in Dublin.