In the early hours of 7 September 1838, Grace, looking from an upstairs window of the Longstone Lighthouse on the Farne Islands, spotted the wreck and survivors of the Forfarshire on Big Harcar, a nearby low rocky island.
She and her father William determined that the weather was too rough for the lifeboat to put out from Seahouses (then North Sunderland), so they took a rowing boat (a 21 ft, 4-man Northumberland coble) across to the survivors, taking a long route that kept to the lee side of the islands, a distance of nearly a mile. Grace kept the coble steady in the water while her father helped four men and the lone surviving woman, Mrs. Dawson, into the boat. Although she survived the sinking, Mrs Dawson had lost her two young children during the night. William and three of the rescued men then rowed the boat back to the lighthouse. Grace then remained at the lighthouse while William and three of the rescued crew members rowed back and recovered four more survivors.
The Forfarshire had been carrying 62 people. The vessel broke in two almost immediately upon hitting the rocks. Those rescued by Grace and her father were from the bow section of the vessel which had been held by the rocks for some time before sinking. Nine other passengers and crew had managed to float off a lifeboat from the stern section before it too sank, and were picked up in the night by a passing Montrose sloop and brought into South Shields that same night.
Grace Darling died of tuberculosis in 1842, aged 26.