She left the shop before switching the gems to the handbag of an unknown woman and the international gang of criminals fled the UK for France in less than three hours.
When the purse in Boodles’ safe was opened the following day, inside were seven small garden pebbles, and the real diamonds have never been recovered.
A proceeds of crime hearing on Friday was told Romanian-born Lakatos, from Saint-Brieuc, Brittany, is expected to be extradited back to France.
The court heard the only money available for her to pay was the 293 euros (around £245) found on her when she was arrested.
Judge Alexander Milne QC said: “As far as the figures are concerned there is a striking contrast between the benefit figure of £4,299,671 and the available assets of 293 euros and 57 cents.”
Since the money has already been seized, he set a one-day default sentence with a month to pay.
Christophe Stankovic and Mickael Jovanovic were jailed for three years and eight months after pleading guilty to conspiracy to steal, over the plot.
