Well, to be honest...girls tease lol that's what they do. However, it doesn't necessarily mean anything x] they like attention and the thought of someone thinking about them, even if they can't have them. Not all girls are like this, but a large majority.
On a brighter note, girls can also be very absent minded, they may say or do things and not even think it would tease you at all.
So signals like "I'm taking a shower brb" or calling you a vampire and asking you to bite her lol...is relatively meaningless either way.
(note: I don't claim to know how every girl thinks, so you never truly know...but that is from my own experience.)