Barbara Stiefel is part of the fifth generation of the Stiefel family, which founded Stiefel Laboratories. The family sold the company to GalxoSmithKline in 2009 for $3.6 billion, and Barbara is estimated to have inherited about $120 million following the sale. 
Ownership of Stiefel Laaboratories was passed down through five generations. Barbara Stiefel’s father, Werner K. Stiefel, once led Stiefel Laboratories’ international operations, with distributorships in about 30 countries. Barbara and her father lived in adjoining condos on Coral Way until he died in 2006. 
Stiefel’s, Charles Stiefel, is a former CEO of the family company. Charles Stiefel donated over $11 million to the M.D Anderson Cancer Center in Houston. 
Barbara Stiefel founded the Barbara Stiefel Foundation in 2010.  Since its founding, the Barbara Stiefel Foundation has supported a number of left-of-center environmentalist organizations, including the World Wildlife Fund, Catskill Mountain Keeper, the Natural Resources Defense Council, the Nature Conservancy, and Ocean Conservancy.  New Venture Fund and the Proteus Fund.  
Stiefel herself is a notable left-of-center donor. In 2012, Stiefel donated over $1 million to the Hillary Clinton super PAC Priorities USA Action through two separate contributions and has donated between $250,000 and $500,000 to the Obama Foundation.  She has also contributed to the campaigns of many Democratic candidates, including those of former President Barack Obama, former U.S. Senator Al Franken (D-MN), and U.S. Senator Elizabeth Warren (D-MA).  Stiefel donated to the PAC People United for Medical Marijuana seven times between March 2013 and January 2014 for a total of $310,000.  She donated to the PAC again in 2016, contributing an additional $50,000. 
In 2019, Stiefel gave $100,000 to the Nancy Pelosi Victory Fund and $88,500 to the Democratic National Committee (DNC).  In 2020, Stiefel donated $100,000 to failed Democratic Florida State Senate candidate Patricia Sigman’s political action committee.  During that same year, Stiefel donated hundreds of thousands dollars to various left-of-center organizations, including Black Lives Matter, the New Hampshire Democratic Party, the Biden Victory Fund, AB PAC, the Arizona Democratic Party, Women Vote!, the Georgia Federal Elections Committee, and Indivisible Action.