You have a blessing. Enjoy it :) Most dog owners have to worry about how to get their dog to stop barking and have to deal with complaining neighbours.
If you are worried about your dog not barking when required, don't think twice. Dogs have great instinct and when they suspect danger they will definitely bark. They will warn you and even guard you. But for that, your dog needs to grow up. As of now, she is a puppy and does not see the need to protect you. She will hide behind you, and expect you to protect her. Just give her some time and she will make you proud with her protective instincts. As of now, just sit back, relax and enjoy her puppyhood :)