even more so against a Pole in Poland.
Then she should stay quiet and then change the locks as I said just before the final month. Then if he tries to break the door down, or sends a gang, she calls the police, they come double quick, she cries attack! and the police cart away the gang.
The trick is that there must be someone in the property to prevent the owner from breaking and entering.
Of course in the meantime the owner can get a court order to get the OP out - but this is Poland, right, and that will take ages.
She needs a man around who will front up to this crim. If I were 20 years younger I would volunteer, and offer him violence.