Gilmer/Gilmore/Lynas/Speight family of Newry

Would anyone have any connections to the Gilmer/Gilmore/Gilmour families of Newry, Armagh, Ireland, in particular the ones living in Canal St, Newry in the 1880's, through to the census records in the 1900's? Also, the surname Lynas/s in this area or elsewhere in Northern Ireland?  Research to date has indicated that the Gilmer family of Newry may have originated in Belfast or had connections there. 

I am trying to find out the origins of my great-grandmother Sarah Gilmer/Lynas/s, born circa 1852, Ireland, who once lived at 31 Canal Street, Newry, where she had four sons with my Speight ancestor from England, on the three birth certificates found for her sons, her "maiden" name is listed as Lynas/Lynass.

Sarah's first born son was given "Gilmer" as a middle name and an Aunt was later given "Gilmour" as a middle name and my late grandfather recorded his mother Sarah's name as "Sarah L Gilmour" in a baby book for my cousin, so there appears to be a strong connection with this Gilmer family of Newry, but I have been unable to find the connection to date, or confirm the correct birth name for Sarah, or find her parents and any siblings. 

I managed to get in touch with one Gilmer descendant and they were able to confirm there was a male Gilmer living at 31 Canal St around the same time (1880's) but had no knowledge of the connections, and I found other Gilmers/Gilmore's in the street (later census records from the 1900s). Sarah "Speight" (on death certificate) passed away in 1891 aged 39 years, at Canal Street, and is believed to be buried at St Patrick's Church, Newry, but I am not sure if she has been buried as Sarah Gilmer/Lynas/s or Speight, and the RCB library told me to look up the GRONI website but I was unable to find any burial index for the church at the time.

There is no marriage record to list the father of Sarah, so there is a whole branch of my family tree that I cannot trace. If anyone has any suggestions, or knowledge of the Gilmer or Lynas/s family of Newry or Armagh, or can help to confirm where Sarah was buried and under what surname, I would be very happy to hear from them.