Passports
Of course, Abby and Brittany each have their own passports because they are separate people. That’s only logical. However, the twins only ever need to buy one airline ticket! Hey, that’s one good part!
Caffeine
Something interesting to note is that each twin reacts completely differently to certain things. When it comes to coffee, it has a different effect on them. Brittany’s heart rate will increase from caffeine, but Abby doesn’t even seem to be affected.