Generally speaking, a judgment expires after 7 years unless the judgment holder takes steps to reinstate the judgment. If the judgment holder took such steps, then the judgment could still be enforceable.
Your question raises a question about whether the original suit was properly served. If you were living with your aunt at the time, the service would be proper and the judgment valid. If you were not living with the aunt, then she would not be a proper party to serve. If you were not living with your aunt, you may be able to challenge the judgment. You would need to have an attorney file a traverse to the garnishment and a separate action to vacate the judgment for lack of proper service. Bottom line is that you would most likely need to hire an attorney that deals in this area regularly if you want to challenge the judgment.
This response does not create an attorney client relationship.