What a great thing you are doing!! I have little ones so I can't give you a lot of help, but maybe a few things.
I am from Indy also, and the airport is usually madness on Friday (well busy for Indy anyway!). We do like getting down there in the evening so we have a full day for a first day, but plan on getting to the airport in plenty of time. I don't know where she goes to school, but in Lawrence Township that Friday is a snow day meaning we get it off if we have not had a snow day. Of course, when booking you wouldn't know this.
We just stayed at the Poly in October and loved, loved it! That said, some of our reasons were because of the little ones - easy and quick access to MK, fun pool, but not an overly big slide for my six year old, big enough rooms for the five of us, and a balcony to sit on while the little one napped. If it were just me and a teen, I would probably think about the Epcot area resorts or my DH and I loved Wilderness Lodge on our honeymoon. It is not quite as expensive. There are people on the resorts board who can answer any question you have about the different resorts!
We are foodies and have at least one sit down meal a day. I am sure my kids think that is what all people do!

Frequent the restaurants boards, and you will learn all you need to know about the different restaurants. I would definitely do at least one character meal just because they are fun! Sci Fi is also very fun and different, but the food lacks - stick to burgers if you decide to try it. Have fun! You are giving her such a great experience!!