Wideman started on the Amherst Regional High School Varsity team for six straight years, beginning in 7th grade. In her senior year, leading her team to the high school state championship, Wideman averaged 17 points, 6 steals, 6 assists, and 6 rebounds per game. In the State Championship game, she scored 27 points, had 14 steals and 8 assists, with 7 rebounds. In 1992-1993, Wideman was named USA Today First Team High School All-American, Converse High School All-American, Nike High School All-American, Kodak High School All-American, New England High SchoolPlayer of the Year, Massachusetts High School Player of the Year, and High School All-American by the WBCA. She participated in the WBCA High School All-America Game in 1993, scoring 10 points. Her high school basketball team was the subject of a book, In These Girls Hope is a Muscle, by Madeleine Blais. While in high school, Wideman published poems on the complexities of her racial identity in her high school newspaper. Shortly after the Los Angeles uprisings of 1992, she wrote and published a poem titled Black.
Wideman was selected as the 3rd overall draft pick by the Los Angeles Sparks in the inaugural WNBA draft of collegiate players in the summer of 1997. Wideman played for four seasons in the WNBA, playing for the Los Angeles Sparks, Cleveland Rockers, and Portland Fire. Wideman spent the 1999–2000 winter season in Israel, playing for the Elitzur Ramla club in the Israeli Basketball League. Her team won the national championship. During the winter of 2005, Wideman reunited with college teammate Kate Starbird and played professionally in Ibiza, Spain.
Activism
Upon graduation from Stanford, and during the offseasons of the WNBA, Wideman founded and directed the Stanford Athletic Alliance. This bi-weekly program paired young women from East Palo Alto with players from the Stanford Women's Basketball team for individual mentoring sessions, as well as group sessions that allowed the young women to explore various academic areas through hands-on experience. In 1997, Wideman founded and implemented another youth program called "Hoopin' with Jamila". This program combined basketball skills clinics with a reading and writing program targeted at young women of color incarcerated in the juvenile justice system in Los Angeles. The program was funded by Nike. USA Today honored Wideman as the "Most Caring Athlete" in 1998, in large part because of the success of the program. The program also earned the National Council on Crime and Delinquency "Community Award", given annually to programs that attempt to provide creative alternatives to juvenile incarceration. In 2001, Wideman participated in the Connecticut Forum, where she shared the stage with Stanley Crouch, Anita Hill, Spike Lee, and Bill Russell to talk candidly about race.
Writing
Wideman collaborated with Juniper Lesnik to publish an article on playground basketball in the Sunday New York Times.
Post-basketball accomplishments
Following her graduation from New York University Law School, Wideman began working as a staff attorney at Equal Justice Initiative in Montgomery, Alabama where she litigated on behalf of death sentences individuals in state and federal courts, and later became a staff attorney at the Legal Aid Society in New York City. In September 2018, Wideman was hired by the NBA as Vice President of Player Development.