Get there early and get a yay or nay. Worse case scenario I've seen is that the proctors will help you coordinate with others and get someone to loan you theirs while scheduling you two in different time slots.
Remember to bring everything on the list. I hate those giveaway flashlights. I forgot to pack my calculator, but managed to borrow one from the front desk clerk at my hotel on the way to the test site. It was one of those arithmetic only big button ones. But beat the hell out of long handing it.
Best of luck to both of you.