We have met around 4 months ago, we both are from the same country and are on an internship abroad. She lives quite far from me (around 400 km). We have chatted a bit since we've met and our communication in real life has been nice.
We are in our early 20s and I like her and would be happy if her stay would result in something more (sex), but I also don't want to be inappropriate and make this visit an uncomfortable experience - I don't know if she is interested in me but I can't be sure she is not interested either. She's single and we've talked previously about her visiting but I was already busy at that time. Now that we've figured out our schedule, she will stay for 2 or 3 days and she'll be seeing my town and do some short trips to the nearest cool places.
I had mentioned to her before that she could come if she wanted to and I'd be glad. She accepted and then (a month after) I asked her if she wanted to come over for a weekend. It was supposed to be a weekend for more people actually, with a car rental and more invited friends but she was the only one who was interested in the end.
I'm not sure that I can read signals from women right, so the questions are:
Which signals could she give me to show her sexual interest? And how to read them right? How do I give her a signal that I am up to more, without making her visit uncomfortable?
I do have two beds in my apartment, so she wouldn't need to share with me if she wasn't interested.
UPDATE: We spent almost 5 nice days together (its a long Easter holiday in Germany). There was no signs of sexual interest from her side (or it seemed me so), no touches and she didn't seem to appreciate them from mine either, she also avoided to look me in the eyes and meet my double-meaning compliments with strange/uncomfortable looks. So i decided to focus on having a good time with her as friend instead of thinking about having sex with her.
Thank you all for the answers, I learned a lot and had a great time. I hope that this question will help someone in the future.