Hello, I don't think any of John's children are Roena's. John's first wife Isabella Bowen died in 1839. Your Robert B Callihan was born in about 1834? That would make him Isabella's child. My only question would be Isabella's records from her gravestone lists her as age 54 when she died. She would have been about 49 when Robert was born a little old but possible.
Where did you see a record about Roena being named Lydia?
I'm related to John H Callihan, I don't have 100% proof but I'm 99% sure that John H Callihan is the son of John Callihan and Isabella Bowen. The George Callihan listed in 1850 census is the son of John Callihan and Isabella Bowen.
My John H Callihan had 4 children that I know of, William born 1845, Mary born 1847, Candace Callihan born 1852 and Robert Harrison Callihan born 1854. Robert Harrison Callihan was my great grandfather. Robert and his brother William moved to Nebraska in the late 1870's.
It also appears that John H Callihan and his wife Nancy died sometime between 1855 and 1860. The children appear orphaned and living with another family in Sewickley PA 1860 census.
Do you have your records available in a GEDCOM, if so maybe we could swap information that way.