I would help her. The world is changing and so is the relationships of Xs. When we were divorcing I wouldn't have but now we have grandchild from our two sons and I don't feel that anyone should be left out at Christmas. We have had my DH x wife for Christmas many times and last year my x came for Christmas.
What happened in our marriage is over and done with. Now it is about the kids and grandchildren. I know that my sons appreciate that we get along "most times".
Life is to short to hate someone for the rest of your life. So if I had a daughter that wanted to make something I would help her.