I am related to the Cardew family (My Great great grandfather Alexander Macpherson married Emma Cardew who was the daughter of George Cardew, brother of John Haydon Cardew (JHC) )
I don't know whether you have this information but the book 'Cornelius Cardew, a memoir by Sir Alex Cardew) tells me the following about Anne Pollet
JHC travelled to Lisbon in June 1791. He met the Pollets there. Mr Pollet was a jeweller who married Anne Sleath on 10/10/1770 in Friern Barnet church London. They had 2 boys and a girl, Anne was born 15/01/1779. Anne Pollet (the daughter)travelled to England in 1793. She married JHC on 04/09/1798. Anne Pollet died 14/01/1851.
I also have a 40 page booklet written in about 1920 which details of 33 Cardews and their descendants (mostly male, and details of their military records.
These include Corporal Colin Loftus Cardew Lieut Leonard Cardew Driver Tottenham Cross Lucas Cardew