The 20-year-old sported the sock bun creation in the first images taken of her at Lima airport alongside Scottish friend Melissa Reid in August this year.
The pair were caught trying to smuggle cocaine worth more than £1.5 million out of Peru in suitcases.
Since images of the two first appeared, Scottish girls have been copying Irish-born Michaella's hair. Top Scots stylists have told how they have been inundated with requests for the hair style.
Wil Fleeson, 43, managing director of Rainbow Room International in Glasgow, said: "We've definitely seen a rise in the number of women asking to have their hair up since these girls hit the headlines. And it's women of all ages coming in asking our stylists how to do them. The doughnut which Michaella is seen wearing in most pictures is really easy to do."
He added: "It's a really strange trend, but it's definitely caught on. I doubt Michaella is aware she has become a hairstyle icon."
Joy McQuillian, 30, who won the stylist of the year title at the British Hairdressing Awards, said the 'doughnut' is popular with both celebrities and the public.
She added: "Lots of celebrities have been wearing their hair up like this from Carmen Electra to Kim Kardashian to Reese Witherspoon."