Q. we live in (xxxxxxxx) it is a remote area. Very few muslims live here. My mother is afraid of death. If the day she passes away there is no woman to wash her body and my dad has also passed away. What is the necessary thing to do to make sure she is washed? Can a man wash her if he is not husband?)

A: May Allah (SWT) award your mother a long life, Ameen.

If no female exists, than the closest male through blood ties must make tayamum (striking the hands on the ground) and wipe the hands over her body. They must not view the parts of the body that are to be concealed; this must be done to the extent that is humanly possible.
If no male family member can be present, then a non mahram must do the tayamum with gloves on and thereafter perform it on her.
Allah Certainly Knows Best