Thanks for your time.
We have the pei records except anything that shows the birthdate of Peter William Costello and Ellen Kennedy. We can only guess by using census info.
After arriving in pei it seems they had:
jane in May 15, 1834, Ellen mar 6, 1836 and finally for the girls Anne on mar 6 1837. The last one was a boy sept 21 1841. We postulate that after the first three boys and ne girl in Ireland they immigrated or between the boys and the other girls, the husband and wife came followed by the Ireland children as It looks like he settled on the farm in 1831 by the 1841 census.
Mary was the last born in Ireland on mar 23 1829 so between that birth and 1831 they arrived in pei. My wall is Ireland for the four births and the marriage. I have searched newspapers etc. Trying to find the orbit that might have the parents birthdate to help find them in Ireland.