
Has your friend had all the manditory health tests done on the bitch and the stud with good results, if not then the KC may not over turn the endorsement. I personally would not have mated a dog I didn't have the all clear on, there are plenty of unregistered pups out there already.
Many endorsements are put in place by the breeder till all the health checks have been done and got good results before they are then lifted, some may also want the dog to have proved itself in the ring or be evaluated by someone well respected in the breed.
An endorsement may have been applied because there is a major problem with one pup in the litter which may be carried by the rest making it very important that the endorsed pups are not bred from.
I think your friend should have contacted the KC as soon as she saw the endorsements on her papers. and found out then where she stood.