[@Framing A Moose] the shadow realm is complicated. If a shadow move (for example she steps into your shadow and you start walking) then she would fall out if she didn't move. Light is a little different.  A big light (like the sun) could force her out. But something that just makes the shadow lighter (grey rather then black) she would be ok be she would have to be extemely careful. She would also avoid shadows tgat are too dark or complete darkness