It's best not to train a dog to be an attack dog unless you are willing to accept the liability. Get a breed of dog that is known to be protective and its instincts will take over if your daughter is bothered. Good protective dogs are preferable to trained attackers.
Find a professional trainer to help you. They will be able to help you train the dog so that it does not become a danger to everyone and you do not end up in a situation where the dog attacked somebody who did not deserve it. Be careful with this idea!
