The death notice for her sister Gillian [Judy] McCarthy states that she had predeceased her sister -
McCARTHY, Mrs Michael (Gillian Madeline [Judy] nee SMITH) 1941 - c2025
She was resident in Owhata, Roratura, New Zealand according to DPB2019 where her forenames are Barbara Elizabeth. A search of
bdmhistoricalrecords.dia.govt.nz doesn't reveal a death for Barbara Elizabeth Harris but there is a registration for Elizabeth Barbara Harris (b 29 Dec 1939 d regd 2024). When searching under her maiden name of Smith the same registration comes up so I am fairly certain this is the lady we are looking for and DPB (and Burke's) have her forenames the wrong way round. I haven't found a death notice/obit.
She was the dau of Sir Thomas Turner Smith, 3rd Baronet of Stratford Place cr 1897 (1903-1961) and (m 1935) Agnes Winfred PAGE. She m 1967 (div 1979) Selwyn Lloyd HARRIS (1939-2007) and had 4 s (one of whom decd)