I'm thinking she's more of an ESFP, but I'm not sure. Part of it is that she'd stay at our house for the occasional weekend, and she doesn't think that there's much to do in our area...but she does want to visit us.
It sounds like she has to stay indoor with you because there's nothing else to do in your area. Must be bad news for ya.
ESFP are touchy-feely, and may take offense to your aloofness. So, I think if you (INTP) need space for yourself (studying reading whatever), the first thing you need to do is to make her like you.
First I would suggest greeting her with a hug.

As an NT you may not be comfortable with that, but this is the easiest way to tell a ESFP that you like her.
Second chit chat with her a bit, and lightly touch her arm when you both laugh at some joke. ESFP like touching more than anything else.
Then settle her with a TV or a bunch of magazines or some movie DVDs. She may want your company but you can suggest that you need to prepare for exam or do some homework and then excuse yourself to your room.
But I think she will need your company sooner or latter. I think you may invite some of your friends to your house when she's there. They probably like the company of a ESFP.
That's all I can think of at the moment... ESFP are not that hard to 'deal with' really. It doesn't take much for them to like people.