Sorry Len for not replying earlier but I forgot to tick the box.
I cannot find any record of her remarrying but then she apparently lived in and around Calcutta for 20 years after the death of her 2nd husband John Foulds and only returned to England in 1955.
Could you also check for a Maud Mann as this was her first marriage and it may be that she never married John Foulds.

The only reason I know that she died on the Isle of Man is because it is written in a couple of articles about her connection with John Foulds.

Does anyone have access to the Registery records at the Library so that I can get the number to order a certificate.