Paige Relyea, of Nesconset, was reported missing by a relative on Monday afternoon.
She was last seen leaving her home Sunday afternoon in a 2009 gray Toyota Corolla with New York plate HSA 5877.
Authorities say her body was found in Syosset on Thursday. Further details have not yet been released.
Nassau County police detectives are investigating, and anyone with information is urged to call 911 or the Fourth Squad at 631-854-8452.
----------
* More Long Island news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube