Nothing can be ruled out, even the possibility that this mysterious girl with the drug in her hands is the very same enigmatic blackmailer whom I hope Ashe will expose. Though I’m not sure that she plans to put the drug in all the alcohol at once. It seems to me that this is planned as a "dirty dessert" towards the end of the party…
Anyway, I’ve decided that my Ashe will either not drink at all or do so very carefully. She still have to catch the damn blackmailer (or at least make progress in the investigation), and for that she needs to have a clear head and not too blue balls.