I have been to the reference library in John Frost Square and according to the Electoral Roll for 1911 and 1912 the only person eligible to vote using Cwmcarvan Court as the property is as follows
Surname, forename/s, title if any, address, Qualifying property
MOCK, Stephen Saunders, Colonel, 2Gwydr Crescent Swansea, Share of house and freehold land Cwmcarvan Court Estate.
There was no other mention of Cwmcarvan Court Estate at all so it would seem that whoever had the other share/s in the house was either not eligible because they were female or they had not botheres to register their right to vote in that district. perhaps they had property in other places and just forgot.
Ann