I don't think pups start teething at 5 weeks, so she must be a little older. (Everyone, please correct me if I am wrong)
As for calming down, the first year most pups are go-go-go.
Terriers tend to be very energetic their entire lives and need plenty of exercise. Start training now to help focus her. Institute a daily routine of activities at about the same time each day and this will also have a calming effect.