I sugest that you try the parish of Killoe and Edgeworthstown. My gg grandmother was Heslin from Edgeworthstown, however I am do not have much more info. She married my gg grandfsther Farrell from Lisnagh Edgeworthstown and their daughter Anne was my grandmother. They remained in Longford and I am not sure if any siblings emigrated. There are two other people who have Heslin from Killoe roots and have a lot of information- IRED52 and katehanley@erols. Hope this helps.