This responds to her inclusion in
Centenarians in Debrett's Part 5 (2026)
This needs confirmation, but I am relatively happy this is a correct identification.
According to a GRO search she died Q2 2010 Lewisham. YoB 1913.
Her address in Debrett's 2008 was in Catford SE6, very close to Lewisham.
Her husband, Baron MELLISH (life peer), was born 1913, so reasonable that his wife was born the same year.