The OP's sister was the one who left the negative. Macy's SAs are NOT trained or authorized to authenticate Coach. Many SAs are not familiar with older styles. Some SAs will even automatically say that an authentic bag is fake if they are told that it was bought on ebay.
This bag is a Signature Shoulder Tote (not a Carly). The style number 7473 is correct for this bag. It's from 2006. I don't see any problems with the bag in the pictures, however, I don't know if the bag pictured in the auction is the same bag your sister received since the seller also sold this bag in another auction using the same pictures:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300449440363
The seller says that she received two of these as gifts.
Please ask your sister to post pictures of HER bag here so we can take a look.