I just watched Batman Rises on HBO, and I didn't get it when Bruce Wayne spoke about the Cat Woman. He said, "But the ground's shrinking beneath her feet". It seems like it may mean "no one can approach her", but I am not sure.
It is a metaphor that means there is less and less room for her to move, as if the ground she is standing on is shrinking. The police/FBI or whoever is investigating her are closing in on her. Eventually she will fall (she will be caught by the authorities).