Behavior: how to calm down a shy/skittish piggy

[EmilyFritzFern]

I am new to the cavy world and recently got a non-breeding pair. They are around 2 years old and haven't been handled very much. We have only had them for 5 days, so maybe there is a long adjustment period, but the female especially is constantly freaked out. she rarely comes out of her house when I am in the room and when I hold her she shakes. What is the best way to get her to relax?? spend more time/less time handling her? will she ever get used to people? how long will it take?