You also need to be very careful about the kids interactions with the pup. Children under the age of 9 (of course there are many exceptions) typically don't have the ego force to handle a puppy properly. Grabbing the pup, chasing and screaming near the pup, leaping into your lap with the pup etc can all lead to some poor interactions. The problem is that many young kids just don't understand the warning growl and won't back away in time before it becomes a bite. The children need to learn how to behave with puppies and You need to make it clear to the pup that growling at the children won't be permitted. But always be sure to reinforce calm interactions with lots of calm praise.
Your wife needs to participate in the training so the pup learns to look to her for advice as well. The more she engages the puppy's mind the more important she will become in the pups life. It's so much more than feeding, walking and playing with the pup - it's also about teaching, setting boundaries and rules, in addition to the love.
Love Them & Lead Them,
~Elizabeth & Doug
Dog Training the Way Nature Intended