Why does a girl always like my Facebook posts and stare at me and if she usually acts uninterested?

A girl I've been crushing on always liked my posts. I couldnt really tell how she felt so I asked her out a couple times shes said no and hasnt offered any reschedule, so I assumed she wasn't interested. However, she likes every single one of my posts, stares at me and smiles at work, asked me how big my feet were for apparently no reason, and I've tried messaging her to gauge her, I may get a little reciprocation, but it usually turns into one word responses quickly...but she will still like everything I post. Shes Mexican so idk if there is just some cultural thing I should be aware of in regards to this either. What should I do? Move