Does she have a crush on me??

Ok, I am very honest while asking this question and writing here. I am a guy just turned 25 and work at an IT company. My office is very far from my home and it takes almost 4 hours of travelling daily. I have got friendly and helpful colleagues in my office and I spend a quality time with them during office breaks.
Now turning to the question, there's a girl which is from some other department in my office. It's been 5 months that I see her usually boarding the bus while standing in the queue to my office. She's a good looking girl but I only admire her looks.
Initially I had thought of her as a egoistic person as she never seemed to speak with anyone else in our office than guys or girls from her own department. But while leaving or coming to the office she usually has got a female friend who is from my department. I never used to speak initially with her friend too, as our group used to be different. I used to notice the girl whenever she used to give a look to me sometimes. Later on due to some kind of work related matter, I had a conversation with her friend after which I used to speak or smile at her friend. I initially didn't even know her name, until a colleague with whom I used to travel by bus told me the same. She used to speak with my colleague. Initially even when used to have close encounters like at wash basin or water filters she never gave me a smile or something, and I too didn't used to bother about her. This happened till a few days back when I finally had a talk with her while we were walking towards the bus station which is half an hour long enough.
Now the day when we spoke for the first time. It was almost 6.30 the time by which I leave the office. The girl had already left the office almost 10 minutes before me with her friend. When I was walking down the street I noticed them walking ahead. These were 3 people, the girl, her female friend and another guy from the office whom I used to speak with too. The female friend noticed me when I came walking behind them. I started talking with the guy and her friend while walking. Later on we got some topic and I started walking with her friend and she continued walking with the other guy. Sometimes she was walking beside me but never began a conversation. I too didn't bother and let it go the way it was going. I sometimes addressed everyone on a joke but never called her name personally. This went on until when just left 10 to 15mins of walking she called my name and addressed everyone that I would have reached the destination if I was walking alone. Later on we began walking together and she began talking with me. I was surpised initially that she knew my name. Then she also revealed that she knew where I stay and started asking why I travel to the office from so far and not stay nearby on a rental basis. She later on began asking who's in my family, where was I born and brought up and what my father does? I was surprised that in our first conversation she asked me all these questions.
Now I am confused whether she has a crush on me? I don't have a girlfriend and never had any. I really have got no time to think about having one as I am more into my career till I settle down. But still I think if this is going to be her, I would welcome the God's decision. I am really confused and don't even know she already has got a boyfriend. I never had a crush on her but after meeting her I think I am changed. Can anyone please suggest me what can this be?
Sorry for a long story, but it matters me.