The news of her death was made public by her publisher, Penguin Random House, as they confirmed the news to the Associated Press. Her daughter revealed to the New York Times that her mother died at NewYork-Presbyterian Hospital due to lymphoma.

Pascal created over 181 Sweet Valley High books over two decades. She worked with a team of various writers over the years to create the series. The young-adult books first debuted in 1983. The series followed identical twins, Elizabeth and Jessica Wakefield, as they navigated teen romances, friendships, and various drama in their fictional Los Angeles suburb of Sweet Valley. The series had various spin-offs including Sweet Valley Senior Year and Sweet Valley University.

The books were translated in 27 languages, having sold over 200 million copies all over the world. It also had an accompanying television series that starred real-life twins Cynthia and Brittany Danie, from 1994 to 1997.

Before she began creating the Sweet Valley series, Pascal worked as a journalist and also wrote the 1960s TV soap The Young Marrieds.

Pascal got divorced from her first husband, Jerome Offenberg, in 1963. They had three daughters together. One of whom was Jamie, who passed away in 2008. In 1964, she remarried John Pascal, who passed away in 2981. Pascal is survived by daughters Laurie and Susan, as well as six grandchildren and five great-grandchildren.