Males praying behind females because the room is small

You have
to try to keep the women separate from the men, even if the prayer-room
is small. All the people – men and women – should know that the back
of the room is only for women. You could put up some kind of barrier
to define the space that is for women, even if it is only a line of
the floor, or a marker, or something like that, so that there will be
enough room for the men who come late to stand behind their brothers
who came earlier, and in front of the women who are praying. And Allaah
knows best.