K.P.
I like the ideas that that the other two moms had. Making sure your daughter does something to celebrate her dad is an important thing to do. You definitely should have a mom and daughter talk to validate her feelings, but also, especially so she doesn't become a depressed teen, talk to her about life. Tell her that you know she is going to hurt for a long time and that you are always there to listen. I'm sure you did this when her dad passed, but it doesn't hurt to reassure her that the door is open. One thing you might try doing to get her thinking of life instead of that her dad is dead, is share a story with her about one of the first Father's Day memories you have about her dad. Maybe something you both made him, or something special you did with her dad when she was a little one. It may be hard for her to open up and talk about her dad with you because you have created a life with someone else and have another child with that person. So by starting the conversation with a cute memory of when you were a family with her dad may make it easier for her, and she may start to talk with you more often.