In the end it seemed appropriate that we "simply" said thank you for each child and at the Amen they threw their confetti in the air. It was a lovely prayer time simple but surprisingly unifying and very calm, but the children were very excited at saying thank you for each child and joined in.
At the end we used a confetti cannon (we did this outside) and I closed the prayer, thanking God for all the church and for us being able to get to know Jesus through the Bible! on the Amen someone let the cannon off (with children suitably reminded that it may be loud, so put your hands on ears/ move to an appropriate place, adults were positioned accordingly too!) The cannon was AMAZING! Totally beautiful and not too loud!
I think this could be used for so many topics of prayers (obviously not too much) for any of the wedding themes, or perhaps pentecost!