What does it mean when a girl is slightly infatuated?

Okay so I was on fb last night-this morning. Talking to my crush from 10:20 to 1:10. During our long, fun conversations she changed her status to "i'm becoming slightly infatuated". I didn't know what infatuated meant, she said it was "obsession". So in the morning I looked at a definition. Turns out she left out some details about what it meant. We have had extensive talks before on fb (and at school) but nothing as long as 3 hours before. During that time we got to bond with each other. We talked about future individual plans that we both have. I felt like great chemistry was there. We got to flirt with each other and we got to speak deeply to each other. It was fun, even if it was through fb. My question is what (in simple terms) does she mean by her being slightly infatuated? I have taken this whole thing slow...very slow, which is perfectly fine with me....as long as it takes. Thanks for any answers