I don't know about Prozac, but certainly some antipsychotics, anticonvulsants, and benzos could increase the likelihood of fragmentary or en bloc blackouts when combined with alcohol. How fast alcohol is consumed could be a factor. Also, are you 100% sure your daughter only drank one drink? Maybe that's all she remembers. Even if the one drink is true, it's possible it could cause memory issues, based on other factors (several). Could some other issue have also been involved (i.e. dissociative symptoms, hypomania, depression, anxiety, etc.)? I'm assuming she hasn't had ECT lately. In any case, I think this should definitely be mentioned to her doctor.