All you can do is your best with the time you have with your WW so any chance you can slip in a nice comment or gesture,do it until she leaves.
Most people here, but not all,agree that once a WS moves in with the OP it is time for Plan B.Why? For one thing,you cannot effectively Plan A your WS when they are living elsewhere and with another person,and,that person is going to be the one trying to fill the EN's of your spouse which is painful to endure on all fronts.That is the time to detach and take care of yourself.
If your WW's family has a difficult time with issues well,there is no time like the present to spill the beans and just let the issue be out there exposed.Don't hide the e-mails either,show her what you have,make copies to send out if requested.You are just keeping her secret still,you see that don't you? I keep hearing resistnece on the exposure suggestions and ultimately,you do what you want to do but if you want our help to follow with the MB guidelines,this is what I am telling you.I understand your hesitation but Dr.Harley came up with these plans because this is what he found to be effective battling Infidelity.
If you are concerned that your WW is going to high tail it out of the state once you begin exposing then get busy getting those legal documents in order pronto.Then you will be a bit more prepared for the possibilties.
One other thing.You will experience many motions during all this which will make you feel like you are nuts,we call it the rollercoaster.One day you're up,the next your down.Most times it's like this several times a day.Be sure to take care of yourself and eat right,sleep well and get professional attention if you need it.Infidelity is a huge trauma and if you want to fight the good fight,you need to be in as good health as possible.
~Good night~
O