With three people working the table, I would suggest just one handles the money.
Also, just one animal out for a customer at a time - no exceptions. Arrange the merchandise on the table so you can tell at a glance if something that hasn't been sold, was taken.
Assume a certain small percentage of people coming to this venue are there to steal. Be esp. wary of anyone who seems to be making a confusion/distraction. Also be extra wary if someone is trying to make you feel rushed.
Cash payment and change are counted slowly and deliberately in front of the customer.
CC's and checks? - insist on ID.
Sounds harsh, but that's sales.
Good luck.