New to the group looking for advice

[h=5]Looking for some advice. I just got a guinea pig, Cookie, about 3 weeks. She came from a home with lots of guineas. I think about 4 altogether. I've read that they are very shy and timid and I have two young very eager kids ready to get to know her. She eats very well and seems to enjoy her cage. When I let her out to run around and play in the main living area she always goes right back to her cage. She's seems very content on not interacting with us much. Is that normal? Is she still adjusting to us? Is there a good/better way to get her to enjoy interacting with us more?[/h]