Doing an interview today

Another assignment I have to do is to interview one of my instructors. So I contacted my one and only instructor, (other than the one who gave me the assignment) and she said she is available today between 1:45-2:45 EST. So I am going to call her, and I have the questions I am suppose to ask as well as my own questions I have. (she is a published author, so you can kind of guess what questions I have for her..lol) Anyways,I have been going over the questions, reading them out loud and really hope I am more clear and not tongued tied as I interview her. (I have messed up a couple times and had to reword some to make it sound clear) Plus I wonder, one tip the instructor said was not to be late for the appointment, but I don't want to call too early. (besides the fact, what if her clock is 5 minutes faster or slower than mine?) So I am think that maybe calling about 1:47 or 1:48 is a good time to call. What do you think?