The GRONI death index shows a death for Robert McDowell registered in Larne on 20th April 1892. That pretty well fits with the date you have given.
For his wife Jane, there is a death registered on 5.5.1898 (the date you have given) in Larne. However that woman was only 56, ie born c 1842. Since that?s the year she supposedly married, I don?t think it can be the right person. There is another death for a Jane McDowell registered in Larne on 21.10.1898. She was 70, so that looks a bit more promising. You can view both death certs on-line for ?2 each on the GRONI website. Use the search death registrations option.
https://geni.nidirect.gov.uk
I found this probate abstract:
The Will of Robert M'Dowell late of Gleno Raloo County Antrim Farmer who died 20 April 1892 at same place was proved at Belfast by Alexander M'Dowell of Ballywillan and Robert John M'Dowell of Ballyhone both in said County Farmers the Executors. Effects ?858 16s. 9d.
You can read the full will on-line on the PRONI wills site:
http://applications.proni.gov.uk/DCAL_PRONI_WillsCalendar/willsSearchResultsDetails.aspx
The will mentions wife Jane and his son Robert (evidently unmarried in 1892). Should he die without issue then the estate was to pass to a nephew Robert John McDowell. Robert?s brother Alexander was appointed executor.
He evidently had property in Ballywillan and Corneal as well as Glenoe. I think this is might be the son Robert farming on his own in 1901:
http://www.census.nationalarchives.ie/pages/1901/Antrim/Raboo/Ballywillan/991388/
There?s other McDowell families in Ballyhone you may want to look at. They look like possible relatives. (Half the townland was occupied by McDowells. There?s probably about 10 of them there). Robert seems to have plot 7 which passed to a John Gardner around 1890.
http://applications.proni.gov.uk/DCAL_PRONI_Val12b/RelatedVolume.aspx?5…