That's one way to go. I'd also like to see you more aggressively do some things to bust up their affair more quickly, and would also throw in "establish (and enforce) some strong boundaries" to that, but yeah, that's one approach.
The other is to try to be her best friend, "win her over," rub her feet and generally kiss her ass. Personally, I've never seen it work, and it will probably completely destroy your own self-esteem in the process.
