Cullys in my family tree are from Knocknashane.We know of James b. before 1790 and son James b. before 1810.Also John b. 1805 to John of Knocknamshane. Samuel and Mathew Cully were having kids in the 1760's &1770'sand went to the same Lurgan Presbyterian church as James and John. No locations were given at that time.
James Cully had a daughter Isabelle born 1826, far too late to be yours.Part of the family later became Culley in Canada and I have no idea if the McCully family of Knocknashane is related.I think the records from this church are missing or partially complete from 1775-1820 due to the revolution.