Winegar was last seen at her family's home in the 100 block of Forest Street on March 21, 1979. She left home to visit a friend and never returned. Prior to her disappearance she had fallen in with a bad crowd and smoked marijuana. Her family, and Winegar in particularly, had gotten threatening phone calls until the family got an unlisted telephone number.

After her disappearance, Winegar's family got an anonymous tip that Winegar had been murdered and her body was in the Winooski River. Investigators never searched the river and the tip has not been verified. One of her sister's friends says she found a clump of blonde hair while fishing in the river in 1985, however. Investigators believe Winegar probably ran away from home and did not meet with foul play. There were numerous reported sightings of her after her disappearance, and a relative claims to have seen her standing in the back of the church at her father's funeral in 1981, but none of the sightings have been confirmed.

Winegar was a student at Burlington High School at the time of her disappearance, and her religion was Roman Catholic. She is the youngest of six children; her next sibling is thirteen years older than she is. Her parents are now deceased, but her siblings continue to search for her. Her case remains unsolved.