Poor dog and poor you. I don't own a dog, only had my grandmother's dog who I loved so much and passed away years ago but I can understand how you feel. And the dog as well. Must be terrifying for her to be separated from you.
The good thing is she'll be happy to be reunited with you again when you land.
Plus a whole new world is expecting her, full of adventure. She'll be happy.
I haven't heard the trick with the shirt but it's a good one.
I've been reading your blog and I know how much you care about her. She's a lucky dog, lucky to have an owner like you, honestly.
She's going to forget this experience soon, won't hold it against you.
Have a safe flight.