The new royal couple is already on the job, just days after revealing their engagement.
Her outfit perfectly co-ordinated with Prince Harry's - he wore a smart navy coat and cream scarf. See PA story ROYAL Wedding.
She said: "I'm excited to really get to know more about the different communities here and smaller organisations that are working on the same causes that I've always been passionate about".
The couple began their day greeting a cheering crowd outside the National Justice Museum.
Just as Lady Diana did in 1981 and Kate Middleton in 2011, Meghan Markle made her first official engagement with Prince Harry by her side. They plan to tour Britain over the next six months to give Markle an opportunity to learn about the country before their May wedding in the chapel at Windsor Castle.
Holly Burdett, who is originally from West Bridgford, Nottinghamshire, but now lives in Sydney, Australia, returned home on the "gamble" that the couple would announce their engagement while she was there.
"I think in these beginning few months and now being boots on the ground in the United Kingdom, I'm excited to just really get to know more about the different communities here, smaller organizations who are working on the same causes that I've always been passionate about", Markle said.
He then smiled when a well-wisher shouted, from three or four rows back behind a crash barrier: "How does it feel being a ginger with Meghan?".
Members of the crowd called out Harry's name, while others held up camera phones to capture the moment, or stretched out their hands for the prince and his fiancee to shake.
Harry and Meghan, who broke the news of their forthcoming marriage on Monday, went on a walkabout in the central English city of Nottingham, spending more than 20 minutes meeting enthusiastic wellwishers.
On the Nottingham visit, Ms Markle wrapped up against the cold in the double-breasted, cashmere wool blend Elodie coat, with classic epaulettes and buttoned cuff.
We have absolutely no doubt she'll ace the Royal Family role. She was also without gloves, so her engagement ring was on display, and carried a handbag - something the Duchess of Cambridge rarely does. A little while later one of Harry's aide took the blooms from her.
She shook hands with men and women, some who had been waiting for several hours to get the chance to meet her.