Unfortunately for most ordinary people there would not be much left in terms of records other than the census returns and records of birth, marriage and death. The exceptions would be people in business or trades that might appear in Directories etc, mentions in Wills etc, or Newspaper articles for some people, or those involved in criminal activities. Women in particular, many married wives and daughters, would often not appear in records between these vital events, especially as the census records after 1911 are not accessible .
Voters list might be worth trying, these would show adults eligible to vote at a particular address, but no other details, Waltham Terrace would be Blackrock County Dublin for Voters, so probably Dún Laoghaire Rathdown archives - I’ve seen some Voters Lists at Lexicon Library Dún Laoghaire, but not sure if these cover Blackrock or just Dún Laoghaire.. I know that some dates are closed for public access.
Do you have a date, or approximate timeframe for Mary at that Herbert Street address ?
I might be able to check it in directory listings… if the address turns out to be flats it may not have a detailed list..
Many Dublin City voters lists are available in the Dublin City Library, Pearse Street.