Strange. Double check that her paperwork has the correct address on all her forms. If it is, then contact USCIS about the mistake. It is their fault, so they should mail a new EAD at no cost to your sister.
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Initial Approval: 11/13/12
1st Renewal: 10-7-14
2nd Renewal: 10/12/16
3rd Renewal: 5/16/2018