I think it may actually be "Her head alright," which I like better because it could not only refer to drugs or feeling euphoric but also contrasts the way the girl's head feels to how the narrator's head feels (most certainly not alright).
I think it may actually be "Her head alright," which I like better because it could not only refer to drugs or feeling euphoric but also contrasts the way the girl's head feels to how the narrator's head feels (most certainly not alright).