Boston Marathon bombing survivor Erika Brannock, 29, a Baltimore area preschool teacher who lost a leg, is accompanied by her mother, Carol Downing, right, as she is released from Beth Israel Deaconess Medical Center in Boston, Monday, June 3, 2013. Brannock and her sister, Nicole Gross, were waiting at the finish line for their mother to finish the race when the bombs went off. Walking behind are Dr. Alok Gupta, left, and Dr. Edward Rodriguez. (AP Photo/Elise Amendola)

Photo by: Elise Amendola

Boston Marathon bombing survivor Erika Brannock, 29, a Baltimore area preschool teacher who lost a leg, is accompanied by her mother, Carol Downing, right, as she is released from Beth Israel Deaconess Medical Center in Boston, Monday, June 3, 2013. Brannock and her sister, Nicole Gross, were waiting at the finish line for their mother to finish the race when the bombs went off. Walking behind are Dr. Alok Gupta, left, and Dr. Edward Rodriguez. (AP Photo/Elise Amendola)