Also perhaps of note: Debrett's 1990 has her marriage diss. 1959, and David Fenwick's address, per probate, as Barhams Manor, Higham, Colchester. Several sources indicate a Maj. Charles Fenwick, L.V.O., late Grenadier Guards, to now live there (the third son mentioned in the Telegraph notice above being Charles); per Debrett's 2008 he was of Higham Place, Higham. Debrett's 2011 gives a Justin Francis Quintus Fenwick (Justin the fifth son mentioned in the Telegraph notice above, which fits with his name) as of Geldeston Hall, Geldeston, Norfolk [I suppose Geldeston being right on the Norfolk/ Suffolk border explains this discrepancy].
Per Debrett's 2008, Benedict Fenwick was of Sholebroke, Towcester, Northants.