The Duke of Sussex met 14-year-old Aleyna Genc when he attended Nottingham Academy on World Mental Health Day. Harry hugged the teenager and played her a voicemail from the Duchess of Sussex.
Aleyna, who has undergone several brain tumor removal operations, has been writing to Meghan for two years after being inspired by one of her speeches on women.
The 14-year-old said, "I've been writing with Meghan for about two years and she sent me a little voice mail and I listened to it.
"I just sent her a letter because she made a speech, and that really inspired me – the speech of her UN women."
Aleyna also gave Harry a cuddle dog for Archie, who was born in May.
The king told the 14-year-old that he had not slept in recent days because of his five-month-old son.
Asked what it was like to meet Harry, Aleyna said, "It was amazing.
"It's just a one-time opportunity … and the fact that I gave it and gave it a present was a great opportunity."
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And it shows clips from Meghan and Harry's last Africa tour.
The headline reads: "Today is International #DayoftheGirl, a day committed around the world and launched by the United Nations to acknowledge the global inequality of the sexes.
"Lack of access to education, MHM-related stigmatization, forced marriage of children, legal or medical inequality or gender-based violence, urgent need to support young women on their path to excellence.
"It's also a day to celebrate and encourage girls to know their value and help them take action to grow into the women they want to be.
"The Duchess of Sussex has long campaigned for the rights of women and girls and at the age of eleven campaigned against sexist advertising, which was then changed.
"No matter what age or background you can influence.
"HRH recently shared a quote during a speech in Cape Town:" Visualize your highest self and emerge as her. "
"To all the young girls who read this today on the International Girl's Day, this quote applies to you."
The post sparked an enthusiastic response from the Instagram followers of the Sussexes.
One replied, "Yes, please, thank you for encouraging all GIRLS in the world."
Another commented, "Always a champion of women from the beginning."
A third wrote: "Very inspirational woman (who has an inspiring husband)."