Flirting or just talkative? She's doing quick glances also?

Es always doing quick glances like looking around. She's tall like me, mascara, long brunette. She seems "fancy", she even drove in a new Honda Sonata Hybrid, soon as she pulled up I could've swore she did a quick glance at me. Maybe I'm imagining things. But whenever she walks in the grocery store it seems like she does quick glances to everyone else also. Also one time she was walking I looked at her & she did a quick smile. A few wks later she came in with some sunglasses, once again being "fancy" I quickly decided to mess with her. I said "you can't wear those" with a smile. She walked a little and smiled at me like "what? Well i'm gonna wear them anyway!" smiling. Some time passed by, I turned around messing with my co worker then she walks pass me looking at me saying "i'm still wearing themm". I look at her trying to think what to say. She starts to walk toward me "why? Why can't I wear them?" tilting her sunglasses down. Then I say "i'm just joking with you" smiling waving my hand, she laughs at the same time with me. Turns around & says "cyaa"

Added (1). A wk later she came in doing quick glances with a little smirk. She did this like twice. My friend caught her and she went around the store real quick. She went to the aisle beside me then changed her mind & came thru my line. I played it cool & she just starts convo & she had to go. Friendly or she's trying to break the waters?

Added (2). I'm your typical 20year old working at this store. She's***

She is flirting