The last Orr entry I see in the First Lurgan records is Margaret Geddes and James Orr , a weaver, having an unnamed child in 1863. There are no birth records of Orrs after that. Thomas and David Henry are born previously. So the couple was using a different church when daughter Annie was born or Annie (said to be age 28 in 1901) is the above child.
David Henry Orr, a weaver, was born in 1860, but he claims to have been born in 1870 in the census, if I read it correctly. I expect all the 1901 census birthdates are off.
James Orr in the 1901 census claims to have been born in 1840 and wife Elizabeth in 1850. Their children, Elizabeth 19 and James 17, suggest that this is your Elizabeth Cranston family as they have been married just over 21 years.
However, this James is a shoemaker and this matches with James Orr and Elizabeth Black who had John in 1832 and Ellen in 1851.
Since I can see only First Lurgan Presby baptisms, I would assume that other churches were used to baptize unknown children. Certainly Elizabeth Black did not give birth to Elizabeth and James in the 1880's, so it is likely that census shoemaker James 60 has wife Elizabeth Cranston 50. Also that shoemaker James likely had a son James who was also a shoemaker. This is not proof, though. Nevertheless, note that James Orr shoemaker had dau Isabella b. abt 1836 who married Joseph Adams in 1852. She was not listed on the baptism listing.
Margaret Geddes's husband was a weaver and son David Henry is also a weaver. That fits well. However, you might see who gave birth to Margaret 19, granddaughter to James and Margaret and living with them in 1901. You could ask for a look up on her parents.
There are a scattering of Orrs in the area with one whose family apparently moved from Armagh to Sligo and back again. You may not be able to find what you want in local churches.
I can't easily find marriages after 1865, but I checked the dates you gave me. There were no Orr marriages within a year of that time.
