I'm in a similar situation, although this is a second marriage for both of us. We're not having a wedding party, so our kids are going to stand at the altar with us. After we exchange our vows, he is going to pledge some vows to my girls, and I'm going to pledge some vows to his kids. Then, we're all going to light the unity candle together. Our kids will light their candles from ours, and we'll all light the center candle together.
If you like that idea, many online wedding sites now offer family unity candles (sometimes called "encore" unity candles) that are perfect for this situation. You can even personalize them, so you can include your daughter's name on the candle. Try www.foreverwedstore.com
Incidentally, I love the idea of him giving your daughter a special gift (necklace, ring) during the ceremony, and dancing with her at the reception.
Best wishes to you and your family!