I have also not found the birth record of Annabella McKnight yet either and the only one I could find was born 24 June 1895 Ballydonnell to a William McKnight and Mary Jane Stockdale: https://civilrecords.irishgenealogy.ie/churchrecords/images/birth_returns/births_1895/02209/1834161.pdf the date is over 10 years from the date of 2 February 1885 that I have for my Annabella's death certificate though and what didn't help is that it doesn't say on the death certificate how old Annabella was when she died.
I can't remember ever seeing a death certificate without an age listed 
In 1970s Northern Ireland death certificates changed as I have the death certificate for one of my great grandfathers who died in 1977 and its the same as Annabella's. In the certificates up to the end of the 1960s it would say Age last birthday but the 1970s at least, don't and I have no idea why they dropped that.
The death certificates from the 1970s they were changed to portrait instead of landscape of the older certificates and they have the following information: 1 Name & Surname, 2 Sex, 3 Date of death, 4 Place of death, 5 Usual address (if different from place of death), 6 Marital status, 7 Date & Place of birth, 8 Occupation, 9 Maiden surname (of woman who had married), 10 Cause of death, 10 Qualification of informant, 12 Address of informant, 13 Signature of informant, 14 Date of registration and 15 Signature of Registrar. So no age at death mentioned.
