Supposedly in Ireland a graveplots belonged to whoever retained ownership of the house
Not always true for churchyards and certainly council cemeteries, such as Dundonald, will have rules in place to determine ownership of plots after last registered owner is deceased.
Taylor Helen Drysdale of 78 Donegall Park Avenue Belfast widow died 8 March 1948 Administration Belfast 25 September to Ernest Dempster Taylor architect. Effects £275 7s. 5d.Not probated until 1956.
Which leads to this record solving the mystery of Edith Mildred Taylor

Belfast News-Letter, 7 Aug.1944: HELEN’S BAY WEDDING Taylor—Milliken The wedding of Mr. Ernest Dempster Taylor, A.R.1.8.A., only son of the late Mr. Gilbert D. Taylor, of Stanwlx, Carlisle, and of Mrs. Taylor, Bannside, Cregagh, and Miss Edith Mildred Milliken, elder daughter of Mr. and Mrs. S. E. Milliken, Roseville, Craigavad, took place on Saturday at Helen’s Bay Presbyterian ...
Milliken Samuel Edmund of Roseville Craigavad county Down secretary died 25 August 1947 at College Park East Belfast Administration Belfast 29 October to Ethel Winifred Sheals widow. Effects £1068 0s. 2d.Belfast News-Letter, 9 Mar.1948: TAYLOR— March 8. 1948. Helen Drysdale. widow Gilbert Dempster Taylor (of Carlisle), and loved mother of Ernest Dempster Taylor, Roseville, Cralgavad. House and funeral private.