The interview was set up through email. She was nice and just wanted to get a feel for you and why you think you'd be a good tutor. I'm pretty sure the job is yours if you really want it. Be prepared to answer how you would handle some situations (such as what you would do if multiple students come in with questions). Honestly though, you can't go wrong. It's a quick interview with no follow up. It's simple and odds are you'll get the job working the hours that you want.