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I don't think it was the address (albeit she needs to correct it with Macy's), as it was a "new" account added. If you have a thin file, relatively new, or if she is carrying some decent utilization on the Macy's these would be factors.
You can have incorrect addresses removed via dispute with the credit bureau(s). I had to do this myself. It's not going to help your score though because addresses do not impact your credit score. Something else caused your score to decrease.
OP, the other replies above are correct. An address has zero impact at all on your credit score. That doesn't mean that the AU account didn't somehow impact your score, as it may have, but it wasn't the address issue.