At the end of ch.3, we are told that Catherine "drank her warm wine and water" while preparing for bed. To me, this sounds like the equivalent of warm milk and cookies, something harmless that a young person might drink every night to calm them down before going to bed. I remember also that MP talks about Fanny needing Edmund to mix her water and wine for her, and in P&P, Darcy suggests a glass of wine to Elizabeth to help her deal with the shock of Lydia's elopement. It just seems as if JA and her contemporaries had a somewhat different attitude towards wine than we do today...