Doesn't want to meet me offline?

Hi girls. Need your help desperately.
Seven years ago I was at school and there was one UBERattractive girl. Of course I gazed at her whenever I had a chance. And the most surprising is that I noticed she was looking at me too! But those times I was VERY shy, stupid, insecure... you name it. It was even worse than now (though it's hard to believe). Her beauty frightened me too. So obviously I never talked to her. But it was clear she liked me then. Oh, recalling all that... what a moron I was, couldn't imagine (((

Then I transferred to another school and after that went to university. A month ago I suddenly remembered her name and found her at social network! I wrote her, she was very glad to hear from me. She said she remembered me. During this month we chatted on several topics. To my perception she likes me as before. But I wouldn't have written this if there was no problem. I tried to ask her not even on a date but just to meet each other three times.

First time (right after getting first reply from her). She just didn't reply me at all (though replied to other messages).

Second time I just asked "maybe we meet some day?". She replied in two hours something like "yes, of course) I wouldn't mind)". But when I tried to make a more concrete suggestion she replied in five days that she had to prepare for exams (and she really had).

Third time she doesn't answer again though it's been only one day (I have almost no hope she would reply me on her own, without my questions).

So, dear girls, please help me clarify this situation. Does it mean she just doesn't want to meet me? Maybe she has a boyfriend or another reason, I don't know. Or maybe she just behaves like any other girl and tries not to make it too easy for me to go out with her?
Do you girls follow such rules? :) I mean even if you like some guy you try not to let things go too fast. Maybe she's just waiting something from me. That I would chat to her more. Or to special topics. Or less. Or just waiting for certain amount of time.
Should I panic or it's OK?

If I liked a guy, I'd have no qualms whatsoever in going off to meet him.

If I wasn't interested in him, I'd put off meeting him and make excuses....or ignore him if he began to be persistent.

Hope this helps solve the mystery

If its been a long time since you have seen each other as well, she might have gained weight, or feels less attractive then she was before. Do you find yourself complimenting her more on how pretty she is or more on her personality, and does it matter to you if she's less attractive. I dont see why shed say she liked you and then disappear when its time to meet other than she has a boyfriend or shes less attractive and insecure.

Go out and meet people the old fashioned way. It's really the only way to tell if there is any chemistry there