KAW - I think that Andy and Lee have some very good points. This is something that W must come to grips with on her own. Let her know that you'll be there for D and that you're not going anywhere but that you understand her need to resolve this with minimal input from you.
Sometimes you need to release the ones you love so that they can try to fly on their own - to discover themselves. It's essential when they're your children. Looks like it is also essential for your W.