Love at first sight or Infatuation?

This story took place at work. I was helping this family at computer. The daughter of the family was in front of me, and she tilt her head backwards and smiled as she looked at me. I ignored it, because I thought it was a friendly way to say hello. I went into the booth back on the register, and her and her mother and sister came in to buy the products. As I was helping her mother, I kept seeing her looking at me from the corner of my eyes. I decided to look at her and at that moment my heart skipped a beat, or irregular heartbeat, or erflies (whatever the feeling is), and she blushed and stared at me longer and put her head down. Couple of minutes later I looked at her and we just giggled together. Was she infatuated with me or was it love at first sight syndrome? I am very undeveloped in this type of emotion cause it rarely happens to me.