Jaster disappeared from Davison, Michigan on May 5, 1979, after an argument with her father. She carrying a green army-style duffel bag, and was last seen walking towards Interstate 69. It has been established that Jaster was employed at two eateries in Mesa, Arizona in early 1980: WAG's Restaurant and Paul Perry's Smorgee Table. One of her coworkers at Perry's described her as a quiet, efficient worker who didn't talk about her personal life. She came to work one day wearing an engagement ring. There has been no trace of Jaster since 1980.

Michigan is listed as the state of record for Jaster's disappearance, as that was the region from which she was initially reported missing in 1979. It is possible that she traveled to Florida after her employment in Arizona in 1980. Both Michigan and Arizona authorities are handling Jaster's investigation.

Jaster is described as artistic and creative. She enjoyed animals, unique jewelry and natural items prior to her disappearance. She was an honor student and basketball at Davison High School, but developed paranoid delusions after graduation and may have been abusing drugs. She spent only one semester at Central Michigan University before dropping out. She was committed to a mental hospital after being arrested in 1977 and diagnosed with schizophrenia, but she left the hospital after two months. Jaster's condition worsened after she left the hospital and she began using marijuana and other drugs.

Jaster's family believes Mark Higham, qho dated her and traveled with her after she dropped out of college, may know her fate. In a 2008 media interview, Higham admitted he lived in Arizona from 1977 to 1999, after which he returned to Michigan. He says he was never engaged to Jaster and never saw or spoke to her after she went missing. He stated she had a lot of problems with her family and was unhappy with her life, and he wasn't surprised she ran away. Jaster's oldest sister and her former best friend don't believe she would have gone for this long without contacting anyone, however.

Authorities believe Jaster was a transient for an extended period of time, possibly decades, after her disappearance. She may have tried to contact her younger sister in 1989; Jaster's sister got a phone call at work from an unidentified woman who hung up before she could speak to her. The caller's identity was never established, however.

None of Jaster's aliases or her Social Security number have been used since 1980. Her mother died in 2005. Her father died in January 2008 and left her a bequest in her will; she has one year to claim her inheritance or she will forfeit it. Her oldest sister is still actively searching for her. She traveled to Arizona in the fall of 2008 to publicize Jaster's disappearance. Her case remains unsolved.