On the south wall of St Margaret's church Westminster is a monument with bust to Mary Brocas. It shows her in Puritan dress within a roundel and a lozenge of arms above (now plain but they were "sable, a lion rampant guardant, or"). The monument is attributed to the studio of Edward and Joshua Marshall. The inscription reads:
Here lyeth the body of Mrs Mary Brocas one of ye daughters and coheirs of Williams Brocas of Ffedding-worth in ye countye of Leicester, Esqr. [Esquire], who departed this life the third day of December in the yeare of Our Lord 1654. For whose pious memory her lovinge sister Mrs Frances Staresmore erected this monument.