She won't redirect her mail for two reasons
1) She says she is 'living on faith'. I gather this means that she is living for a few weeks with one of people from her church and then moving on and living with another member.She has told me she hasn't been getting unemployed benefits because if she does the government expects her to try for a whole range of jobs and she is an 'artist' and she wants to concentrate on that, this means she cannot afford to rent a place.
I obviously don't know how things work down there, but here, the mailman mustn't deliver any letter unless the recipients name is on the mailbox (/door). Couldn't you just tell the mailman not to give you mail that isn't yours? -alternatively change her address to Att: her church.