The 18-year-old world number 150 booked had no idea she'd get this far so made arrangements to fly back to the UK at the end of qualifying.
However, after reaching the semis at Flushing Meadows, New York, with a straight-set win over number 11 seed Belinda Bencic, Raducanu had to change the date on her ticket.
Speaking after her victory, she said: "I didn't expect to be here at all.
"My flights were booked at the end of qualifying, so it's a nice problem to have.
"It definitely means a lot to be in the semi-finals.
"I'm just really enjoying the experience.
"Out there on the court, I was saying to myself, this could be the last time you play on Ashe, so might as well just go for it and enjoy everything."
But one drawback to her incredible run is that with the world still bogged dow by travel restrictions owing to the COVID-19 pandemic, her parents Ian and Renee have been unable to fly out and enjoy the experience with her.
Having been unable to join her courtside thus far, they won't be permitted to watch today's semi final (9.9.21) against the Greek 17th seed Maria Sakkari either and Raducanu says "they just really want to see how I am".
She said: "It's not possible, because you need a waiver and it takes a couple weeks for approval.
"It's too late and they won't be able to get one.
"I haven't actually called my parents for quite a while.
"Earlier this week they were ghosting me, but when we speak - because I have been away for so long now - they just really want to see how I am."