Not 100%. Because of The Tonight Show and Good Morning America, it would be an insane schedule.
I could see her doing Alan Carr, Graham Norton or another interview/performance here another time
I'd love her on them shows, it would be hilarious
I think Rihanna flew over in a similar manner for the X Factor so it is possible. She'd have to go out of her way to make an appearance though, she could fit it in her schedule, but it's going to be a tight squeeze. I hope she does it, it will guarantee her a 5th #1.