In 1918, she was convicted of forging bank-notes and in 1920, while in service in Brighton, she was found guilty of stealing clothing and was sentenced to two years' penal servitude.
The Isle of Wight is immediately opposite France across the English Channel and commands the Solent which is the sea approach to the major ports of Southampton and Britain’s biggest naval base, Portsmouth.
With her husband away on war service, O'Grady was seen frequenting restricted coastal areas while walking her dog, sometimes at night.
She was also found guilty of two offences under the Official Secrets Act; that she had approached a prohibited place and that she had made a plan that might be useful to the enemy.
She then sought to give her account of events and in an interview with Sidney Rodin, a reporter for the Sunday Express, she asserted that the whole episode "was a huge joke" and that "being sentenced to death gave her the biggest thrill in her life".
These disclosed that the maps O'Grady had drawn of the Isle of Wight’s coastal defences were accurate and would have been of great assistance to any German attack on the island.
Unknown at the time, as part of Operation Sea Lion, the Germans intended to invade the island with an assault by the Wehrmacht’s 9.Armee under Generaloberst Adolf Strauss.