The girl's mother took to Twitter late last month, telling Miranda her daughter, Aubrey, had tickets to see "Hamilton" but was heartbroken when the performance in Jacksonville was canceled because of the coronavirus pandemic.
"Seeing 'Hamilton' has been her dream since she saw her 1st Broadway show last year," the mom wrote.
Instead, Aubrey spent her birthday watching "Mary Poppins Returns."
"At least we're safe & healthy," the mom's tweet said.
Krasinski invited Aubrey onto the second episode of "Some Good News," his new online show aimed at highlighting uplifting stories during these tough times.
"Very sadly there was one little girl whose dream could not come true because her long-awaited 'Hamilton' experience was canceled," Krasinski said. "Luckily she toughed it out though, turning to the one person she can always count on, Mary Poppins."
With that, up popped Aubrey. Krasinski and Blunt promised the girl they'd fly her family to New York and get them tickets to see "Hamilton" when the COVID-19 pandemic subsides.
The 9-year-old's face instantly lit up, but the surprises didn't end there. Miranda "Zoom bombed" the interview with some good news of his own.
— MAB (@mabauman) April 6, 2020
"I think we can top that right now," he teased. "If you can't go to 'Hamilton,' we're bringing 'Hamilton' to you."
Aubrey then watched in shock as Miranda and more than a dozen cast members, each at his or her own home, sang "Alexander Hamilton" from the hit show.
"Aubrey's still asking if she was dreaming," her mother tweeted a short time later.
Miranda has been spreading joy elsewhere as well. Monday, he sent a video message to health care professionals at NewYork-Presbyterian Hospital. New York has emerged as a coronavirus hot spot, with more than 67,000 confirmed cases as of midday Monday, according to the Johns Hopkins University Coronavirus Resource Center.
"I know you all have families," he said. "I know you are putting yourselves on the line. You never asked for this. You are heroes and you're doing incredible work. I'm grateful for your service. New York City is grateful for your service."
This article originally appeared on USA TODAY: 'Hamilton' cast reunites for surprise performance on John Krasinski show