People do that??? Don't think I've ever heard of anyone sending a 'thank you' type of email for an acceptance/scholarship email... I've heard of people doing it after an interview, though.
I imagine as a teacher you would make a pretty good tutor and there has to be some demand for tutors either in high school or college classes in Chicago.
You can mention that you sent an earlier and that you wanted to follow up to confirm on your interview date. It's not something you should stress out too much over as follow up emails are common, as with admission counselors being busy