I think you mentioned she is not 2 yet? I have stopped doing preliminary x-rays on my dogs. I have found that they are so gangly and loose before they are 2 that often times the vet says these hips won't clear and when x-rayed at 3 they get a good OFA rating. OFA requires dogs to be 2 years old to certify hips, I have my Irish Setters done at 3 years when they are done growing, I have had 75% Excellent ratings in the last 10 years. I am glad the Breeder is standing behind his guarantee, he should replace her.
Maybe waiting til she's 3 would be a good idea.