Former terrorist suspect Nawal Msaad was warned by the judge not to associate with other defendants in the Old Bailey.
It was one of three warnings issued by the judge who had also lost patience with her habit of turning up late at court.
Msaad, 27, had become friendly with a defendant in a separate trial who was 20 years older than her but cannot be named for legal reasons.
During a break in his trial he wandered into her court, plonked himself down between press reporters and started waving and winking at her in the dock as she shyly smiled back.
After he left the jury sent a note asking the judge who the stranger in court was.
The Common Serjeant of London Nicholas Hilliard QC ordered an inquiry and censured Msaad for associating herself with other defendants at court.
It was the third time she had been admonished by the judge after arriving late in the dock and holding up the trial twice before.
Msaad, 27, was cleared by the jury of being concerned in an arrangement to make money available for the purposes of terrorism.
She had hidden 20,000 euros in her underwear when she was stopped at Heathrow before boarding a flight to Istanbul where she allegedly had planned to pass the money to a committed jihadist to fund terrorism in Syria.
