Sarah is very active in supporting two of her favorite charities: Habitat for Humanity and Make-A-Wish Foundation.

Habitat for Humanity is a nonprofit, nondenominational Christian housing organization. They rely on volunteers to "build simple, decent, affordable, houses in partnership with those in need of adequate shelter. Since 1976, Habitat has built more than 100,000 houses in more than 79 countries, including some 30,000 houses across the United States".

In 1999, Sarah spent a few weeks of her summer hiatus in the Domincan Republic working as a volunteer with Habitat for Humanity.

Make-A-Wish Foundation is a favorite of the Buffy people. It is an organization that grants the wishes of children with life-threatening illnesses, through the help of private donors and volunteers. Over 83,000 wishes have been granted to children around the world since 1980.

Sarah frequently contributes autographed materials to auctions on behalf of the Make-A-Wish Foundation of Los Angeles.

In 2001, Sarah donated and helped raised funds for the victims of the September 11th attacks on the United States. She collected over $60,000 from the Buffy group and donated 2 gowns to The Glory Charitable Auctions to benefit the Widows' and Children's Fund of the Uniformed Firefighter's Association.

Sarah participated in Ford's 2003 Tied To The Cause Breast Cancer Awareness campaign benefiting The Susan G. Komen Breast Cancer Foundation. Her ad, which first appeared in August, is one of several showing celebrities wearing the "Ford breast cancer awareness scarf in a national ad campaign designed to garner attention for this important cause".

She has also donated 2 pairs of jeans for The Jeans for Genes Auction to benefit the National Hemophilia Foundation. Several well-known celebrities gave signed jeans for the cause. Sarah's contribution helped raised over $7,000 for this charity.

The wildfires in Southern California in late 2003 touched Sarah so much that she visited San Bernardino County to see firsthand the devastation that this area suffered and the tragic losses endured by its residents. She is helping with the fund-raising campaign to replant the scorched terrain and stop further disasters such as land/mudslides from happening.

Sarah continues her charitable work by custom-designing a pair of jeans for Clother Off Our Back, an organization helping children in need.