Ancestry has an index to some marriages in S Africa. This records one half of the marriage
Name: Helena Thomlinson
Gender: Female
Record Type: Marriage
Marriage Date: May 1875
Marriage Place: South Africa
Spouse:
Notes: Widow
Collection: Simon's Town: St Francis Marriages, 1813-1877
Archive Name: St. Francis Church Simons Town
Entry Number: p.59
extremely vague citation
Ancestry.com. South Africa, Marriage Index, 1807-2007 [database on-line]. Lehi, UT, USA: Ancestry.com Operations, Inc., 2016.
Original data: Various sources from across South Africa.
I knew that Family Search had images for South African Anglican Marriages but they are unindexed.
I looked at what should be the right page but didn't find it
"South Africa, Church of the Province of South Africa, Parish Registers, 1801-2004," database with images, FamilySearch (https://familysearch.org/ark:/61903/3:1:33SQ-GTW5-XS4?cc=1468076&wc=SFVC-GPK%3A44975801%2C44975802%2C47802001%2C47837101 : 21 May 2014), South Africa > Cape of Good Hope > Cape Town, Simon's Town, St Francis of Assisi > Marriages 1849-1955 > image 32 of 266; William Cullen Library, Wits University, Johannesburg
But this church also has its own index book that has also been filmed
These two images record the marriage (more probably banns as per last edit)
Index St Francis of Assisi Simon's Town, Cape Town, South Africa
"South Africa, Church of the Province of South Africa, Parish Registers, 1801-2004," database with images, FamilySearch (https://familysearch.org/ark:/61903/3:1:33S7-9TW5-CWY?cc=1468076&wc=SFVC-YWG%3A44975801%2C44975802%2C47802001%2C47824601 : 21 May 2014), South Africa > Cape of Good Hope > Cape Town, Simon's Town, St Francis of Assisi > Baptisms with index, 1814-1932, marriages with index, 1813-1819 > image 85 of 109; William Cullen Library, Wits University, Johannesburg
"South Africa, Church of the Province of South Africa, Parish Registers, 1801-2004," database with images, FamilySearch (https://familysearch.org/ark:/61903/3:1:33S7-9TW5-CHW?cc=1468076&wc=SFVC-YWG%3A44975801%2C44975802%2C47802001%2C47824601 : 21 May 2014), South Africa > Cape of Good Hope > Cape Town, Simon's Town, St Francis of Assisi > Baptisms with index, 1814-1932, marriages with index, 1813-1819 > image 103 of 109; William Cullen Library, Wits University, Johannesburg
Edit:
looking earlier in the index suggests that this entry, together with others that have a page number but no marriage entry, might come from a banns book but as there is no marriage in the register then the marriage itself took place in another church. (or not at all!) That would explain why there is only a month and not an exact date. Unfortunately there are a large number of Anglican Church registers to search These are from the Cape
https://www.familysearch.org/ark:/61903/3:1:33SQ-GTW5-XS4?owc=SFV7-C6J%3A44975801%2C44975802%3Fcc%3D1468076&wc=SFVC-GPK%3A44975801%2C44975802%2C47802001%2C47837101&cc=1468076