Bologna FC are away at Catania this weekend (kick-off Friday at 8.45pm). So no live football. But there is so much televised football in Italy that you might find a bar that is showing the game. If so, watch it and take in the atmosphere.
If you arrive in time, of course.
Climb at least one of the Twin Towers.
Eat ice cream.
Eat the best food in Italy.
Walk around the market. Walk around the city centre generally and pop into wherever takes your fancy.
Giggle at the Neptune fountain, when you find the right spot to view it from (your daughter should enjoy...