My puppy growls at strangers and has even nipped at a few younger kids... can this be fixed?

She is an 11 month old chocolate lab with extremely good bloodlines and other than this problem she's a great, obedient dog. She very rarely nips at kids, but not hard enough to break skin. I don't want to have to get rid of her, but I also don't want to wait and see if she actually hurts someone. Is there anything I can do to stop this behavior or are we going to have to get rid of her?