Anna Elwood was described as a widow in the 1861 Census. She died in 1864 and is buried at Abney Park - I guess the above quote should refer to 'Mrs Elwood'?
The National Archives Wills Calendar www.willcalendars.nationalarchives.ie/search/cwa/details.jsp?id=1639415130 suggests that he died on 17 Apr 1858 in Co. Roscommon.