You were right about the spelling ,Tybroughney is in the parish of Templeorum. Piltown is the biggest village in that area. There are three churches in the parish and so probably three grave yards. These would be fairly small so you might have luck in finding her grave. I am not sure how the various parishes keep track of burials. You might try writing to the parish priest. Keep in mind that these Irish parish priests do not have office staff to deal with queries and I know that many of them find that Americans write for information giving very little information! The family name you mentioned is quite unusual that should be a help
