This is so tough. Don't try to mind read what W is or isn't doing.
If I were you, I'd get someone else to represent me as a realtor. Fire W as your "realtor." I wouldn't want to have W to do it as she's breaking apart the family. You would want someone outside who isn't involved nor invested to help you broker the land sale.
I was going to ask this same question.
Other than that, I have nothing really to offer but hugs. Just make sure that this is for YOU and not in an effort to impress/win back the WW.