I am odd women out too. I was happy when the kids moved out. No empty nest syndrome here. DD went to college, lived on her own for several years, when we moved across the states, she came with us and has lived with us since. She is 34. She cannot afford to live on her own, so we are stuck. Even tho we get along great, enjoy each other and doing things together, I would love for her to move out on her own again.
I wish you well. You prepared her for this and she will do fine. Be supportive in their marriage and encouraging.