A.H.
My advice is to keep everyone busy. Nothing falls flatter in a party than boring time. Even with the baby; have games for adults and children like charades and have separate tables for things like coloring and painting for the kids and card or board games for the adults. The same advice holds true for the 16 year old, but you have had so much great advice already I will just add-KEEP THEM BUSY!! Good luck to you.