She is portrayed by Kelli McCarty.
Beth was the product of an adulterous liaison between Alistair Crane, and Edna Wallace. Though the two were "intimate" together neither were aware of each other's identity at the time, and wouldn't realize who the other was until nearly thirty years later. Beth was born to Edna who may or may not have been married to Mr. Wallace. Beth assumed Wallace was her natural father until her true paternity was revealed in 2005. After Wallace died, Edna - a former Prostitute, returned to her former profession, despite a job as a server at the Crane mansion. Beth would be abused by the various men Edna "enlisted". When Beth was young she took her rage out on her pet gerbil, various school classmates, and finally her own mother - physically maiming her so that she walked with a walker.
Beth was Luis's high school sweetheart, and managed the Book Café. She was Sheridan's first female friend from Harmony, and when she and Luis dated in 1999, they spend a lot of time with Hank and Sheridan, who were also dating. Sheridan and Luis found themselves spending more and more time together, which upset both Hank and Beth when they learned their significant others were being duplicitous.
Beth was seldom seen for quite some time, until after Sheridan's body was found in the ocean. She and Luis became close again, and even became lovers, with Luis finally believing that he could commit to her, as he was no longer concerned he would leave her like his father left his family. Beth and Luis were looking forward to their future together when Sheridan returned to town going as Diana, with Luis's brother Antonio. Sheridan soon regained her memory and Luis again turned away from Beth.
When Sheridan's pregnancy was announced, Beth went so far as to kidnap her (with the help of nurse Charlie) and kept her in a basement pit while faking her own pregnancy. Luis, who had passed out after being drugged by Beth, had no reason to suspect he was not the father of a child he believed existed. Beth even convinced Harmony doctors to lie for her, and when the time came, she "gave birth" to a healthy son, whom she and Luis named Marty. Not long after, Sheridan was found alive, but her child was presumed to be deceased. Luis grieved for the baby, and spent all of his time comforting or chasing Sheridan, spending little time with Beth and Marty.
Although Beth still loved Luis and was still determined to have him, she also grew very close to Marty, whom her mother, Mrs. Wallace, was helping her to raise. Sheridan became convinced that Marty was her son, and after a DNA test proved Beth was the boy's mother, Beth realised that she was Alistair Crane's daughter. After a second DNA test proved Sheridan was Marty's mother, Alistair helped Beth flee the country with Marty. Although Beth was upset to lose Luis, by then it was far more important to her that she not be separated from Marty, whom she had come to think of as her own child.
Luis finally caught up with Beth in Italy, while Sheridan was back in Harmony with her new husband, Chris. Luis watched, in horror, as the train carrying Beth, Marty and Alistair exploded, and returned to Harmony to tell Sheridan that her father, half-sister and only child were dead. Although Beth never returned to the series; the return of Alistair and Marty to Harmony, implies that Beth is alive as well.