I'll keep this short this time because I have said it too many times before. I think we should ALL read as much as possible but there are just some things that don't go well together. DB is compatible with a LOT of other author's ideas about relationships and such but it does conflict with some also. I feel that any philosophy that advocates ultimatums and forcing the issue of an affair, conflicts with DB's more "hands off" approach. There are a LOT of people in the world who would call us crazy for doing what we do in DB but at least for me, it's worked. I "let" my W continue her affair and sure enough, it ended right around the 6 month mark, as predicted. Now, am I sure it's over? Nope, but I am sure that if I had "kicked her out" it would likely not be.
While it IS harder sometimes to have the WAS living with you, there are undeniable positives too. The biggest of which is that you get the chance to have daily, extended contact with the WAS so she can see the changes you are making. The obvious downside is that it's often MUCH harder to detach and make the necessary changes when she is right there in front of you, reminding you every minute of what is going on.
All I can say is that in DB/DR the idea is to stop focusing on the A, and yes, let it continue while you focus on yourself and making the changes that will have the greatest effect on you and your relationship.]
In the end, it's a decision you have to make, to ask her to leave, or get a temporary seperation. MANY people here have done that and it's worked for them while many others have made it work without doing that. Look at the situation, determine what's right for YOU and then move forward with it.