Hi the Will Calender entry for moses Lowry died 1850 is available through the Proni site, this links him to William Galbrieth and to Raymochy, the image for the entry is also available, had a quick read through but don't see mention of Esther Lowry(Graham) He does mention a son Moses in the Will
The Will of Moses Lowry late of Killyverry County Donegal Farmer deceased who died 9 July 1850 at same place was proved at Londonderry by the oath of William Galbraith of Dooish (Newtowncunningham) County Donegal Farmer one of the Executors.
Regards
Joe