Most Helpful Girl
I think if she's working at night, she's seeing friends during the day. Maybe she's reserving nighttime to see you. That's usually a better indicator that she doesn't have to look at the clock and it's more of a romantic time to see a new date. I think if she really wasn't interested she wouldn't have even called you much less answered you right away. Just text her tomorrow and tell her you're thinking of her and wishing her a good night at work.
Most Helpful Guy
Probably not interested.
What I'd do, is toward the end of the week, send her a text saying something about her letting you know what day she's open so you can meet up. If she's too busy again or whatever, then she's definitely not interested and you can just delete her number.