behavior and personality

by mandi
(panama city, florida, usa)

i just got a jack russell puppy. she is 12 weeks old. i have had her for about a week, and she hides in a corner and acts like she is scared all the time. i spend time with her all day trying to make her feel more comfortable, but it seems as if it is not working, she is still acting the same way. is there anything i can do to help her feel more comfortable and get her to be more active?