Was this girl waiting for my move?

So I was at lunch today, sat on a bench next to the river having a sandwich. It's a sunny day in the city.

I see a girl turn around from a car parked next to the road. I assume she's just left it and is waiting for someone to get out of the other side. Nope, as it turns out, she's on her own. She starts walking past and as she goes by she blatantly looks out of the corner of her eye to see if I'm looking (I am). She stops about 15 metres to my right, leaning against the railings, her back turned to me. She's then either looking out across the river or checking her phone.

I decided to see if she looks up at me over the next 5 minutes and use that as a signal. She doesn't.

I can't help but wonder if she was waiting for my move or not, or if she was just curious if a guy was checking her out.

I know that I'll never know and there was only one way to know for certain, but still - what do you think? Unfortunately I've been embarassed a few times when I act on suspicions like that, while I also know some girls just enjoy attention to stroke their ego and nothing more.