Dat, will you be staying over in Bze city or connecting straight to AC?
I know that I did not like spending too much time in Bze city..its a city! I don't much like cities...most anyways, but its tolerable and has some interesting things to see. If you are headed directly for AC then you most likely won't even leave the airport between connections.
I have never been to AC (did hit Caye Calker) but your wife should read these posts...I say "Ditto" to what everyone else has said, well at least as far as for the parts of Belize I have visited!
My 2 most important suggestions...insect repellant/sunscreen and a hat!

Enjoy!