Someone once asked...
Someone answered with kindness...
You never can, until you both express how you feel out loud. Women are a mystery, one of the best mysteries, but also one of the hardest to understand. And that is okay. But don't forget, someone has to be vulnerable first, and it is better to be vulnerable first and learn that she doesn't like you than to never be vulnerable and never learn that she does like you, maybe ever or maybe just until its too late. Having done both, I recommend the vulnerability.
Wandering voices — answers no one has read yet
Another soul answered...
Probably ask her opinion