Many thanks for all your replies.
The Martha Welply who is my ancestor was apparently just called Martha, without her mother's maiden name Orr which may perhaps have been given to sons but not daughters. I'm saying this on the basis of her marriage certificate dated 1852, which confirms her father's name. To be honest I've not researched Martha's siblings. Incidentally I'm thinking that her residence at the time of her marriage was Enniskeane which is only 3 or 4 miles from Kinneigh.
I'd not seen the Church of Ireland list, which has two entries for Kinneigh, one showing that the records were lost while the other says that some records (maybe roughly those copied on the Paul Turner site) are at RCB under ref PC51. If I'm right, I'm assuming we need to wait till visits to the RCB are allowed before we can check for thye supposed 1820 Martha baptism?
As for the 1863 marriage mentioned below, Martha died in childbirth in 1862, and her widower James Orr Burchill then married her sister Eliza in 1863.