This crate is supposed to be large enough for a Dane. If that won't work for you, though, you could try an ExPen, which can be configured in multiple shapes, doesn't have a top, and would fold down for storage. Or use a baby gate in a hallway. Anything that would confine her to a small space would probably have a similar result.

This is great sized crate for a full grown great dane. Depending whether you want the double door there is also this. Also a note that these usually don't come with the plastic pan that's pictured -- so be sure to check on it.