Sharkey was born in New York City. Her father and grandfather worked in the garment industry, as did her mother, Mona Sherman, who became the president of Perry Ellis America when Sharkey was in high school. She attended the University of Pennsylvania, spending a semester at the University of Paris: Sorbonne, and earned a Bachelor of Arts in International Relations.
Sharkey began her career as part of the team that introduced HDTV to the US market and the media industry, and, as part of an HDTV task force, she lobbied Congress at the age of 22. In 1995, she worked with Barry Diller to create the format for QVC's short-lived sister network Q2, Sharkey also co-founded iVillage in 1995, and served as its chief community architect and head of programming. It became the largest online destination for women, and was sold to NBC Universal for $600 million in 2006.
Sharkey registered the domain names socialmedia.com, socialmedia.net, and socialmedia.org in the late 1990s. She was one of the first people to use the term "social media".
In 1999, after creating the interactive and online brands for Sesame Workshop, Sharkey was recruited by America Online's vice chairman, Ted Leonsis, to join AOL as a senior media executive. At AOL, she oversaw multiple business units and led community programming initiatives, including the development of "People Connection" and aol.com. She remained at AOL until 2006, when she was appointed chairman and global president of BabyCenter LLC, a wholly owned subsidiary of Johnson & Johnson.
At BabyCenter, Sharkey built a site for parenting and pregnancy that served more than 100 million visitors in 22 worldwide markets. She led Johnson & Johnson's initiative with the U.S. State Department for the Mobile Alliance for Maternal Action (MAMA). Announced by US Secretary of State Hillary Clinton, and developed with the cooperation of the White House, MAMA served women in low-resource settings from South Africa to Bangladesh and India. New and expectant mothers register their due date or their babys age via mobile phone in order to receive text messages which provide relevant developmental, health, and nutritional information.
In 2013, Sharkey was appointed CEO of Sherpa Foundry. Founded by Shervin Pishevar and Scott Stanford, Sherpa Foundry partners with public companies to identify, define and co-develop ideas and innovations through external resources.
In 2014, Sharkey met Ido Leffler, the co-founder of Yes To, Inc. and Yoobi, among other companies, and in 2017, they launched Brandless, an e-commerce site described by Fortune as "the next Procter and Gamble for millennials." Sharkey serves as the company's CEO.