Tell her to get herself onto the electoral roll ASAP by visiting or ringing the council. Contact the mailing preference service so you don't get loads of junk mail, and contact your post office by letter to the local postmaster., stating that you are no longer willing to accept fmail sent for Mrs Smith etc and list the names of the people. Good luck - as long as a company has an address to write to they will be very " thick" at removing your address from a database, as it at least gives them somewhere to attempt to chase the debt. I once had the the Inland Revenue and "the baliffs" knock for a previous owner. The I R were the nicer of the two!