Bristol Palin

Bristol Palin attends the Candie's Foundation 2011 Event to Prevent benefit gala on May 3, 2011, in New York.

Bristol Palin attends the People/TIME White House Correspondents' dinner cocktail party on April 29, 2011, in Washington.

Bristol Palin reacts to her mother's speech during the Reagan 100 Opening Reception and Dinner at the Reagan Ranch Center on Feb. 4, 2011 in Santa Barbara, Calif. (Photo by Kevork Djansezian/Getty Images) — Kevork Djansezian/Getty Images

Bristol Palin reacts to her mother's speech during the Reagan 100 Opening Reception and Dinner on Feb. 4, 2011, in Santa Barbara, Calif.

Bristol Palin visits "Good Morning America" on Nov. 24, 2010, in New York.

Bristol Palin performs the jive with partner Mark Ballas on the "Dancing with the Stars," Monday, Nov. 22, 2010, in Los Angeles.

Bristol Palin arrives at ABC's "Dancing with the Stars" 200th episode party on Nov. 1, 2010, in Los Angeles.

Bristol Palin attends The Candie's Foundation Event To Prevent Teen Pregnancy at Cipriani 42nd Street on May 5, 2010, in New York.

From left, Bristol Palin and TV personalities from MTV's "Teen Mom," Maci Bookout and Farrah Abraham, attend "The Harsh Truth: Teen Moms Tell All" Town Hall Meeting sponsored by The Candie's Foundation at Lighthouse International Conference Center on May 5, 2010, in New York.

Bristol Palin, left, and Dr. Drew Pinsky attend "The Harsh Truth: Teen Moms Tell All" Town Hall Meeting sponsored by The Candie's Foundation at Lighthouse International Conference Center on May 5, 2010, in New York.

Bristol Palin attends "The Harsh Truth: Teen Moms Tell All" Town Hall Meeting sponsored by The Candie's Foundation at Lighthouse International Conference Center on May 5, 2010, in New York.

Bristol Palin attends the Candie's Foundation town hall meeting on teen pregnancy prevention at The TimesCenter on May 6, 2009, in New York.

Actress Hayden Panettiere and Bristol Palin attend the Candie's Foundation town hall meeting on teen pregnancy prevention at The TimesCenter on May 6, 2009, in New York.

Actress Hayden Panettiere,left, poses with MVP for the Tampa Bay Rays Matt Garza, and Bristol Palin on the red carpet during an event to promote National Teen Pregnancy Awareness Day on Wednesday, May 6, 2009, in New York.

Bristol Palin, right, daughter of then Republican U.S vice-presidential nominee Alaska Gov. Sarah Palin, holds brother Trig Palin while sitting next to boyfriend Levi Johnston on day four of the Republican National Convention in St. Paul, Minn., on Sept. 4, 2008.

Pictures: Levi Johnston

Bristol Palin, right, sits with her boyfriend Levi Johnston on day four of the Republican National Convention on Sept. 4, 2008, in St. Paul, Minn.

Pictures: Levi Johnston

Bristol Palin and Levi Johnston are seen at the Republican National Convention in St. Paul, Minn., on Sept. 3, 2008.

Pictures: Levi Johnston

Bristol Palin and Levi Johnston stand on stage during day three of the Republican National Convention on Sept. 3, 2008, in St. Paul, Minn.

Pictures: Levi Johnston

Republican presidential candidate Arizona Sen. John McCain gives the thumbs up before leaving the stage with his running mate Alaska Governor Sarah Palin and her family, left to right, her daughter Piper, Levi Johnston, daughter Bristol, son Track, husband Todd carrying baby Trig and daughter Willow, after Palin's speech at the Republican National Convention in St Paul, Minn., on Sept. 3, 2008.

Republican vice presidential candidate Alaska Gov. Sarah Palin, right, stands with her family at the airport in Minneapolis, Minn., on Sept. 3, 2008. From left to right are Palin's son Track, daughter Piper, daughter Willow, who is holding Palin's youngest son Trig, Levi Johnston, daughter Bristol and Palin's husband Todd.

Bristol Palin, right, holds hands with boyfriend Levi Johnston as they await the arrival of Republican presidential candidate Arizona Sen. John McCain at the airport in Minneapolis, Minn., on Sept. 3, 2008.

Pictures: Levi Johnston

Bristol Palin holds her brother Trig during a rally for her mother, Alaska Gov. Sarah Palin, and presumptive Republican presidential nominee John McCain at the Ervin J. Nutter Center on Aug. 29, 2008, in Dayton, Ohio.