What did Lydia darragh do to help the US?

Lydia Darragh was a Quaker, a pacifist, who lived in Philadelphia while it was occupied by the British in the Revolutionary War. The British at first requisitioned her family's house for quartering officers, but she was able to persuade them to allow her to live there with her youngest children. On the evening of December 2, 1777, British General Howe, headquartered in a neighboring house, and his officers demanded the use of a room for a meeting, and told Darragh's family to stay in their rooms. Concerned due to the secrecy, Darragh managed to find a place to listen as the officers planned a surprise attack on George Washington and his Continental army two nights later at Whitemarsh, 8 miles away from Philadelphia. On the morning of December 4, she set out for the Rising Sun Tavern, a known message center for colonists. There she encountered Colonel Elias Boudinot of the Continental Army. As he recorded in his private journal, "a little poor looking insignificant Old Woman came in & solicited leave to go into the Country to buy some flour. . . she walked up to me and put into my hands a dirty old needle book, with various small pockets in it." Boudinot told the woman to wait for an answer, but she left. Curious, Boudinot opened the needle book and found a rolled-up piece of paper on which was written the information that "General Howe was coming out the next morning with 5,000 men, 13 pieces of cannon, baggage wagons, and 11 boat on wheels." Boudinot quickly reported back to Washington, and so the British troops that night found the Continental army awake, alert and at arms. The attack was repelled, and Howe was forced to return to Philadelphia.

It is also possible that Darragh had spied on Howe's activities and sent messages to General Washington earlier, as claimed by her daughter many years later, but the Whitemarsh incident is the only one corroborated by external evidence.