Nooky is more likely if she comes by and sees the tree already decorated ...
Really, the advice here is usually to detach and not pursue the spouse. Inviting her is a type of pursuit. If she initiated and called and said, "hey, I'd like to be with the kids and decorate the tree", then I do think you should allow her to come over. After all, it would be good for the kids to have that with them mom and dad.
