I mean yes they're obviously vibrating and at a different wavelength so that you can't see it staring out into space just like all the different earths in the Marvel/DC universes or in the TV show Sliders aren't taking up the same exact same space. She still created extra stuff so that stuff has to displace something. We don't know if other world travelers even saw them or can see them. If they can be seen from someone or something coming into our system do they ripple occasionally? Would it be like occasionally spotting a cloaked Klingon bird of prey where you're not sure you saw something for a second?