Liz Foster worked hard at her menial job on a factory assembly line at Chancellor Industries ever since her husband Bill had abandoned her and her young children seven years earlier. Liz also supplemented her income doing housework at the Chancellor estate. Her 23-year-old son William Jr. resented being named after a man who would do such a thing, so instead was called "Snapper" after his "snappish" personality. Snapper was putting himself through medical school with a part-time job, and as the "man of the family" contributed to 21 year-old-old Greg's law school, and kept a big-brotherly eye on his 18-year-old sister Jill who worked as a shampoo girl and manicurist to help support them all.

Liz wished the best for all her children and encouraged Snapper to pursue a nice, well-bred girl like Chris Brooks, daughter of the publisher of The Genoa City Chronicle. But with enough obligations already, Snapper preferred his freedom. So while he dated Chris, he also slept with Sally McGuire, a waitress at Pierre's Restaurant. Just after Sally became pregnant, she discovered that Chris and Snapper were about to be married, and attempted suicide. Liz found out about the pregnancy, and convinced Sally not to interfere with her son's budding career and impending marriage, and to marry her boss Pierre who was in love with her. Pierre married Sally knowing that Snapper was her baby's father, but Pierre was killed in a robbery of the restaurant before the baby was born. Sally's baby was named Pierre Charles after her husband, but was called Chuckie. Not long after Chris and Snapper were married, Chris became pregnant, but she had a miscarriage when she found out about Chuckie, and Chris and Snapper separated for a time, but were later married.

Liz's son Greg had fallen in love with Chris Brooks as well before she became his sister-in-law. Greg overcame his feelings for Chris because of her involvement with Snapper, and fell in love with Gwen Sherman. They planned to marry, but shortly before the ceremony, Greg discovered that Gwen was a prostitute. The marriage was postponed, and Greg tried to help lead Gwen out of prostitution. But Gwen's pimp used physical force to pressure a terrified Gwen into continuing to accept clients. Greg finally persuaded Gwen to press charges against her pimp. With prostitution behind her, Gwen experienced a spiritual awakening and left Greg to devote her life to God as a nun. Later, Greg married and divorced Nikki Reed, and during that time a hitman arrived in Genoa City with plans to kill Greg, but he accidentally shot Liz instead. Liz recovered from her injuries.

When his mother fell in love with Sam Powers, Snapper finally convinced Liz to have their father Bill declared legally dead. Unknown to Liz and her family, Bill was alive and living in a town nearby. Penniless and diagnosed with cancer, Bill sent a letter to the family. Liz invited Bill to move back into the house, and with the exception of Snapper, the entire Foster family embraced Bill's return. Although Bill realized that he still had feelings for Liz, he put her needs above his own and encouraged Liz to continue with her plans to marry Sam. But Liz broke off her engagement to Sam because as far as she was concerned, she was still a married woman. This delighted Jill and Greg, who had hoped Liz and Bill would resume their marriage.

Liz's youngest, her innocent daughter Jill, joined Liz and went to work for the wealthy alcoholic Katherine Chancellor as a paid companion, and ended up falling in love with Kay's handsome husband Phillip. Jill got pregnant by Phillip, but on the way back from divorcing Katherine so he and Jill could marry, Kay picked Phillip up at the airport and drove him off a cliff. Although Jill's father arranged for Jill and Phillip to be married in Phillip's hospital bed, Phillip died of his injuries before Jill had his son Phillip III. Katherine later had the marriage invalidated because Katherine was drunk when she signed the papers.

Bill and Liz remarried, and Snapper finally reconciled with his father, but Bill's cancer progressed quickly, and the doctors doubted that he would live out the year. Bill was eventually hospitalized and put on life support. He pleaded many times with Liz to pull the plug and let him die. Because she didn't want to see her husband suffer, Liz agreed to his wishes. But Liz was so traumatized by doing so that she suffered a stroke and forgot that she did it. So Snapper, who was also Bill's doctor, was accused of killing his father. Luckily Greg was now a practicing lawyer who got Snapper cleared of murder charges, and Liz was never charged. Soon after, Jill fell for David Mallory, a young man who was blind until a cornea transplant restored his vision. The eyes he received were from the deceased Bill Foster.

Liz began seeing her daughter-in-law Chris's widowed father, newspaper publisher Stuart Brooks. Although Stuart was quite taken with Liz, she felt she was not of his class, and she avoided becoming romantically involved. Jill saw her opportunity in Liz's reluctance, and still looking for a rich man to provide for her and her son, Jill pursued Stuart. Stuart resisted Jill's advances, but she eventually spent a weekend in Las Vegas with him. Soon after, in a sly attempt to trap Stuart into marrying her, Jill announced that she was pregnant. Stuart agreed to marry Jill even though he was in love with Liz, who was heartbroken by the news. Shortly after the marriage, Jill accidentally fell down a flight of stairs. When Stuart questioned her doctor about Jill's pregnancy, he was told that Jill was not pregnant, and Stuart realized that he had been duped. Jill refused when Stuart told her that he wanted a divorce. But when Derek, the man she really loved, was free to marry her, she quickly divorced Stuart. In time Stuart and Liz were married, although Liz was daunted by her new life as the wife of a successful newspaper publisher. On the same day as their parent's wedding, Snapper and Chris had a baby girl, Jennifer Elizabeth Foster, named after both grandmothers.

In 1982, Snapper left Genoa City to accept a three-month fellowship opportunity in London, but Chris refused to give up her modeling career at Jabot Cosmetics. Not long afterward, Chris realized her place was with Snapper, and she joined him in London. Liz, Stuart, and Greg moved to London as well by the end of the year.

In 1984, Liz returned to Genoa City a widow, to be with Katherine during her face lift and attended her ex-daughter-in-law Nikki Reed's wedding. Liz was there for Jill after Jill had been shot by her former masseur Sven, and Liz welcomed her grandson Phillip home from boarding school. But in 1986, Liz returned to London and moved in with Chris and Snapper where she devoted herself to help raise her granddaughter, Jennifer, who had two hard-working parents.

In July of 1993, Liz returned to Genoa City in response to a call from Katherine Chancellor telling her that her daughter Jill had given birth to a son by her husband John Abbott. Liz was pleased to find that Jill had named her son William Foster Abbott after her late father, Bill, and was to be nicknamed Billy.

Out of the blue in 2003, Liz arrived in Genoa City with Snapper and Greg from their home in England with the news that she was about to undergo brain surgery. Knowing she may not survive, Liz felt it was time to admit to Jill that she had been adopted. Liz told her that her husband Bill had brought Jill home as a baby wrapped in a blanket. After a DNA test, Jill believed for years that her arch enemy, and Liz's good friend, Katherine Chancellor had been her real mother. But another DNA test proved that Katherine was not, and Jill's parentage again became a mystery.

In November, 2008, Katherine was believed to have died, and Liz returned to Genoa City for her old friend's memorial service. Katherine was later found to be alive, and her doppelganger Marge was the person they buried that day.

In June 2010, Liz returned to Genoa City to see Jill, but was carried off the plane on a stretcher, accompanied by Snapper. Jill and Kay met them at the hospital, and Greg arrived later. Liz was diagnosed by Snapper with Wegener's disease – a rare, autoimmune disease. Fearing she may die, Liz confided one last secret about Jill's parentage to Snapper. Snapper told Katherine, saying that he knew what it was like to regret keeping a secret, as he had about his son Chuckie, so he intended to tell Jill the truth. Each of them spent some final time with Liz talking mostly about the past and Jill. Later as she had been about to finally tell the secret to a very distraught Jill, Liz passed away. Afterward, Snapper told Jill that her real father was a very young Neil Fenmore who had gotten a girl pregnant. Neil's family had refused to let him marry the girl, so she had abandoned her baby at the hospital and committed suicide. Lauren Fenmore was disbelieving when Jill told her the circumstances that made them half-sisters, but later looking at old photos of her deceased father, she shared the news with her husband Michael. Michael promised to find out the truth. Since Liz had requested no services be held, Snapper and Greg were preparing to leave as Jill returned home with the news that she had spoken to Lauren. Kay let the brothers know that she would look out for Jill. A DNA test proved Liz's story was true, and Jill was indeed the daughter of Neil Fenmore.