I don't think she wants to stand on her own two feet. There are two other feet still in the picture and they're not yours. Women don't leave to be alone unless they absolutely have to (abuse, cheating husband). She might want to leave, but not to be alone. You need to find out what is really going on or you don't have a chance to fix it.
I would concur with this. Were you able to find out more about OM?
Me-LBH, 48 Spouse-WW, 48 Married for 19 years Son, 12 BD #1 - November 1998 (EA 7 months after wedding) BD #2 - November 2015 (same XBF EA) WW filed D February 2016 WW moved out April 2016