Well I was feeling really down about this latest hiccup, but today brought good news!
I heard back from Gretchen (the person handling our file with USCIS) today and she said that due to information that I was able to provide them about another page in our home study that says "the couple is approved...child 0-18 months..." she was able to get a supervisor to approve the change on our approval letter without us submitting an update form (and the accompanying $360 fee) AND she had already completed that and mailed it out this morning! Wahoo!
I figured that we would still have to go through all the notarization/authentication process again with the other copies of our home study (dossier, etc)...but sufficeth to say that Chareyl figured out how we could take care of that too! So, we should have this little problem (that could have been time consuming and fairly expensive) all taken care of in the next few days!
I will be excited to announce when we receive our corrected USCIS approval soon!!!