If you didn't see her due to a SUV blocking your view there is a good chance she didn't see you . This may not be the case but I think you may have been riding in a blind spot which can be created following trucks in traffic also.
After a while you will start to look out for things like the hand on the steering wheel start to move as the approaching vehicle starts to cut you off.
I know a guy who runs cheap 12 volt halogen household downlights on his crashbars to get noticed and I've read on here other people talk about getting more lights up front.
