Sent you details of gravestone earlier by PM. Notice that you mentioned Mary E. Andrews probably related to Mary Annie Andrews but possibly not sisters.
Samuel Andrews, son of John Andrews, Gortfad was baptised 12 Dec.1849 Main St. Presbyterian Church (mother's name not recorded at that time). Samuel Andrews (carpenter) married Ellen Malone and had:
1. John born 16 June 1876, bapt. 20 Aug.1876
2. Samuel born 14 Feb.1878, bapt. 12 Mar.1878
3. James born 14 Feb.1878, bapt. 12 Mar.1878
4. Ellen Jane born 18 Apr.1879, bapt. 13 July 1879
5. William bapt. 23 Oct.1881
6. Mary Elizabeth bapt. 18 June 1883
7. Maggie born 5 Oct.1887, bapt. 9 June 1888
1901 Census- Samuel Andrews and some of the family living in Garvagh (mistranscribed as Sarvagh)-
http://www.census.nationalarchives.ie/pages/1901/Londonderry/Garvagh/Sarvagh/1519987/1911 census- widow Ellen and 2 children still in Garvagh-
http://www.census.nationalarchives.ie/pages/1911/Londonderry/Garvagh/Garvagh/590941/Death for Samuel Andrews July/Sept.1906 Coleraine district (age 56) is in civil index.
1901 census- Gortfad- Stewart Andrews, sister Rackel Rankin and niece Mary E. Andrews:
http://www.census.nationalarchives.ie/pages/1901/Londonderry/Glenkeen/Gortfad/1520232/(from other records- Rachel Andrews married 1863 John Rankin, Cah, daughter of William Andrews)
1911 census- Stewart Andrews in Gortfad with cousin William Andrews:
http://www.census.nationalarchives.ie/pages/1911/Londonderry/Glenkeen/Gortfad/591305/Death registration- Stewart Andrews Apr./June 1915 Coleraine district (age 85)
- Rachael Rankin death Apr./June 1907 Coleraine district (age 84)