I would personally put them in your checked items. Just wrap clothes around them to protect them and you should be fine. If there are breakable things, ask the store where you get them from to pack them in bubble wrap or give you extra paper for your plane flight back. The last time we went on a flight, they checked our checked luggage as well, so to avoid your little ones seeing their surprises, have them sit down somewhere you can see them and give them something to do (book, game, etc.) that way they're not interested in that. Or you can tell the airport employee you don't want your kids to see what's in the bag and to please be discreet with your stuff.
Have fun!
Christiana