I can't be married with someone who isn't sure what she wants.
It may help you to reframe this: I won't be married to someone who chooses someone else over me.
Because I'm not sure you've really come to terms with that. All W's talk about not being sure is code for I don't want to have to choose--I want both of you. Unless you can verify that she is no longer in contact with OW and has definitively ended that R then you have to assume that she is still involved with OW.