It honestly sounds like the author is desensitized to sweetness and dislikes bitter things in general. It's amazing how cutting out sugar/added sweeteners in general can greatly increase ones sense of taste. A little sweet can go a very long way. After a few months without sugar, eating a typical U.S. sweet treat feels like complete overload.
I've noticed this in a lot of my friends also. The ones that have attempted cut out sugar have all experienced the same.
Of course she could just dislike wine, which is completely fine. But all of the other things mentioned lead me to believe this might be a part of it.