According to a GRO search she died Q1 2021 Somerset.
She m 1948 (as his 1st wife, diss 1963) 5th Baron CROFTON, 2ndly 1964 (diss 1972) Robert Thomas Francis FLACH, 3rdly 1973 (diss 1976) Guy BROOKE. After her 3rd divorce she resumed her maiden name. She had issue by her 1st marriage: 4 sons & 1 dau, including the 6th & 7th Barons. Of her children, only her dau outlived her.
If I am reading Debretts correctly it appears that the 5th Baron's second wife (Mary FRIEND) had previously been married to Robert FLACH (ante) - what a world!