Congrats on the job interview!

I'd e-mail her. If you're not sure what her e-mail policy is, then you can hardly be blamed for violating it, now can you Then take a breath because IT'S ALL GOING TO BE OKAY!

You might need to miss the week with T. See if she can talk to you on the phone instead. Alternatively, if you get the job, remember that you're there because they WANT you to be. And so you just say, "I've got an appointment at X time on X day." It is amazing how, when you say a thing with warmth and confidence, people just say, "oh, okay," right back at you. No problems. If they have a problem, hey, you'll cross that bridge when you come to it.

Wishing you the absolute best!