Go to dinner, but prepare yourself to go with no expectations. That way you will not leave yourself open to being hurt. Enjoy it for what it is and enjoy your D. Think of it as bonus time with your daughter.
Make sure you look good, smell good and ask what you can do to help out. Better yet, pitch in, whether it's helping with the baby, dinner or clean up.
Do not initiate any R talk and do not tell her you love or miss her. You've told her once and she knows it.
Go and have a good time and leave your W with a good impression.
