In my experience being a woman and a lesbian, women are not only hard to read and difficult to understand, but to make things even more complicated, sometimes they literally aren't aware of what they want...
So what my experience is telling me is it really could be anything. Some women play with others because they like the attention or they like teasing them and it's a social game like the way dogs play with each other with bones, not with any intention at all of looking for a romantic relationship. It's like social exercise or something to that effect. On the other hand, some people are brought up in houses where it's appropriate to be more touchy-feely whereas others don't so depending on her background, this could either be normal behavior for this girl -- something she might do to a cousin or brother regularly -- or something more meaningful and thus, indicative of real feelings. In addition, it's also possible this girl might like you and she herself isn't really all that aware of it.
I've found that the only way to be sure is to ask in a partially joking way. If someone were doing this to me, I'd probably say: if you keep stroking my hair like that, people might think you have a crush on me...<insert chuckle here> Addressing a serious topic that isn't morbid in joke form helps to get rid of some of the pressure so that she won't feel as embarrassed or uncomfortable as if you, say, went out and said to her: hey, do you have feelings for me?
This non-serious approach, though longer and more drawn out than simply asking: do you like me or not? is really much better accepted by people (specifically NTs) in my experience. I think it's because when their feelings are out in the open, they get scared so not drawing direct attention (by joking rather than being direct) helps them to feel not so vulnerable and exposed.
I know this situation is rough. I've been there and suffered from the situation of NTs, especially, being playful without any intent to follow through or just being contradictory. It's confusing and frustrating and messy, but I hope my insight on this helps. I've been there many times so I feel your pain. I hope however things work out, that they're for the best for you.