If you want to stay married, I think having her in the house is a good thing if you can handle it emotionally and GAL without pursuing her or letting her cake eat. Were it me, I wouldn't bring it up and would simply go about my business with detachment and working on yourself.
I would make sure the financial situation is equitable though, and that she is carrying her weight there.
I also agree with everyone who suggested you not leave the house for any reason. Going on a trip or holiday visit I would think is ok (doesn't hurt to check with a L in your state). But physically separating can be presented in a lot of ways and is an escalation. You can't prevent her from doing that, but there may be legal implications if you find yourself down that road so I'd stay as long as there is no abuse, and I'd check with a L.
