Thanks for the responses. I feel caught in the middle. I can understand the Dad wanting to date again, and wanting to move on with life and living. At the same time, the kids are still grieving. This is the first major event and my niece getting married is the one who was very close to my late sister. That is why I can see having a picture of her on the alter. I just don't want anyone to be crying. I want it to be a happy event. I want to keep spirits up.