My husband and I deal with the nips, but our 5 year old jerks her hand back even though we are trying to tell her to touch their back and not their face so they don't nip...but yes...difficult.
I see adults doing that too with dogs, the jerking the hand back thing. The dog doesn't even need to bite to do damage. A hand or finger accidentally too close to teeth as the dog bounces around + a quick pull back = torn skin. So regardless if you end up keeping the pups or not, I'd definitely work on teaching the 5 yr old how to pet a dog safely.