Ok so here I am again with a lady of interest and questions about whether I'm interpreting things optimistically or if I'm right.

So I frequent a certain fast food restaurant but have not been back there for awhile so this girl was new to me. Anyway long story short, I pulled up to the drive through window and since my car's power window is broken, I had to open the door and get out to go pay. kind of awkward but anyway... As I approached, I just stated matter-of-fact that "my window is broken" to the girl taking my money. Now it's hard to place this but the way she regarded me and smiled at the time "seemed" like interest or attraction. Now I am not one to assume women think I'm interesting or attractive typically as I dont' really think that much of my looks or anything so I'm rather skeptical but I'll be honest, it really caught my attention and made me curious because there really was something seemingly there in her behavior. Anyway it was brief and she followed up with "have a lovely night/evening! (not sure I remember which she said)" and Off I went but for the rest of the night I could not shake the feeling that there was something that just happened.

so the next night I took a chance. I just wanted to confirm my suspicions and this time I went inside the restaurant. I was at the counter ordering and I noted she was working the drive through area again. She actually walked toward the front for whatever reason but when she looked over and saw me, she started smiling, like visibly happy. Now as a skeptic one might think it was just a friendly thing but to be honest, I can remember thinking "wow, she is interested." I don't think that easily about women as I said so it kind of underscores her reaction, I think? as I ate I did notice her come out a couple of times doing whatever... in the front but I can't say 100% that she came out and looked over at me more than briefly.

Anyway am I being too hopeful or how do I interpret this more realistically?