Maxwell, along with her fraternal twin Christine, was born in 1950 in France to Elisabeth and Robert Maxwell. Following her graduation from Oxford in 1972, she gained a Diploma in Education (French) from the University of Edinburgh before beginning her career in film and television production.
In 1981, Maxwell moved to the United States and began to collaborate with Dale Djerassi whom she married in 1984. They co-produced the feature film '68 (released in 1988 by New World Pictures) and the 1982 PBS documentary, Bhutan – A Strange Survival, introduced by the late Senator Charles H. Percy of Illinois and narrated by Ludovic Kennedy. Michael Aris, the late husband of Aung San Suu Kyi, served as adviser and writer. In 1982 Maxwell also wrote and directed Grays Inn - A Fountain of Justice, narrated by Ludovic Kennedy as well.
Maxwell was a co-founder, along with her husband and twin sister, of the company behind early search engine Magellan. Isabel joined sister Christine who was leading a small company called Research on Demand that was online in 1993"". The company changed names to McKinley Group and became a search engine with ratings. Isabel served as a senior vice president (David Hayden "", her second husband, was CEO and her sister was publisher). In early 1996, the company was poised to IPO, but investment bank Robertson Stephens decided to put Excite on the market first. A few months later, IPOs became difficult and the startup company was running out of money. Magellan wanted to go public with Lehman doing the offering but was unsuccessful. Michael Wolfe's book Burn Rate also describes a failed deal to combine with Wolff New Media, which shortly later went broke itself. With money running short, Isabel's husband was pushed out by investors and her sister left. Isabel resumed the responsibility to dispose of the company. After a layoff, the firm was sold for $18 million (of stock) to competitor Excite.
From 1997 to 2001, Maxwell was the president of Commtouch, Inc., an Israeli-American e-mail messaging and security company. The company went public on NASDAQ in 1999. As of 2012, the company remained independent.
From 2003 to 2004, Maxwell was invited by Blumberg capital to become CEO of iCognito "", renamed Puresight, an Israeli web content filtering software company. She turned the company around, and it was sold in 2005 to Boston Communications.
Maxwell is a founding member of Israel Venture Network founded in 2001 by Eric Benhamou; she has been Director of the Board since 2008. "" From 2004-2010 she was Chair of the IVN Social Entrepreneur Fellowship Program. "", Video on YouTube,"". She speaks often for and on behalf of IVN at conferences such as WEBBIT in Istanbul in Turkey "" and has developed and emceed IVN conferences both in California and Israel.
She has been an invited and active member of the International Governing Board of the Peres center for peace since 1999 "" and is on the governing board of the American Friends of the Yitzhak Rabin Center "".
She works as a consultant for startup companies and venture capitalists.
Maxwell and Djerassi divorced after eight years together. They had a son, Alexander. She later married dot-com entrepreneur David Hayden; that marriage also ended in divorce. In 2007 she married Al Seckel, but this marriage was not official, as Seckel was still legally married to his previous wife. She lived with Seckel in Malibu, California, then moved to France with him in 2011 after fraud charges were filed against Seckel in a federal lawsuit, a case in which Maxwell was named as co-defendant. Maxwell and Seckel filed for bankruptcy in connection with this case, claiming to be destitute, but their claim was rejected according to court documents available from PACER (law), the federal court website. They lived in Chateau de la Malartrie in La Roque-Gageac, and acquired thousands of stone-age tools to sell in the U.S. In December 2015, after reporting that Seckel had died in an accident, Maxwell was declared bankrupt by a British court.