Thank you hallmark, gaffy, Sinann, and myluck! for your help. I had the baptism records for Sophia and Eliza from a source other than the NLI website - I didn't know the Catholic Parish Registers were viewable online until today, thank you especially for that. I didn't know about Mary and Thomas.
The year of birth I have for Patrick Martin does seem very suspicious now. I got the information from an indirect descendant of Sophia Martin in Ireland (she's the granddaughter of the sister of the wife of one of Sophia's sons - don't know if there's an actual name for that in a relationship chart). Eliza Thompson's year of birth seems okay. I'll check with my informant where she got her information from.
In the meantime, not having anything more than the name, I guess the Patrick Martin recorded in the Griffith's Valuation could be anybody.
Thanks again fo your help. Much appreciated.
