It is a long shot, but on our WBTA in 2016, the Excursions Desk on the Magic had a small scavenger hunt card available each day at sea with 10 fingernail-size themed photos on them. The themes ranged from chairs, pictures (twice), uniforms and carpets. Each photo would be of a small section of one of these items and your challenge was to find them (all over the ship), write name and location below the photo and submit it by 10 pm to the same desk. All the winning cards were put in a container, shaken up and one was drawn to receive a
DCL prize. This is not as easy as the Detective Agency challenge, believe me. This is a heck of an adventure for adults. We passed other folks doing the hunt in the hallways and had to, literally, had to exchanged notes on some of the items to complete our card. We loved it! Don't know if it is only available on longer cruises, but worth checking on your cruise. Your kids are old enough to enjoy it. Note: the uniform one is a bear.
As I remember, on another recent Magic cruise, they had a Tangled-themed scavenger hunt for large symbols (static cling) from the movie/show, again, all over the ship. Believe the hunt was on our bed night prior to the Tangled show. When completed, you gave it to your room steward and, if correct, you got a treat on your bed that evening. This is similar to the Frozen one.
Don't know if this helps. Our grandkids, their parents and their parents (us) love these hunts. Maybe one of the themes above might help you. Good luck!