Determening an actual interest with a girl?

I told a friend of mine that I really like her (and believe me I do). Thing is she 's from another country. I don't know how she may take that. She said I was really nice. I asked her out a few hours after I met her. Things were just so great it felt like the right thing to do. She accepted and we swaped cell numbers. We couldnt make the date and she went back to her country shortly after that. We keep in frequent contact by phone, email, IMs. She's planning on imigrating to the USA soon. makes me happy. What I don't understand is she told me, that I'd have to wait 2 years b4 she gets here. She hasn't said she like's me. She has said that she really wants to see me. I mean she's 17 right now. I'm 23. but does that matter? I dout it will in 2 years either way you look at it but, I'm interested in her. How do I know if she's messing with me, or if she's interested in me like I am in her? Is there anything I could ask her to find out? I really need some advice. Good advice.