From wikipedia:
Sampson fought in several skirmishes. During her first battle, on July 3, 1782, outside Tarrytown, New York, she took two musket balls in her thigh and a cut on her forehead. She begged her fellow soldiers to let her die and not take her to the hospital, but they refused to abandon her. A soldier put her on his horse and took her to a hospital. The doctors treated her head wound, but she left the hospital before they could attend to the musket balls. Fearful that her true identity would be discovered, she removed one of the balls herself with a penknife and sewing needle, but her leg never fully healed because the other musket ball was too deep for her to reach. On April 1, 1783, she was promoted and spent seven months serving as a waiter to General John Paterson.