Hugs sheneedshelp,
Welcome to SR, keep reading and posting..there is much to learn
Remember the 3 Cs
You can't cure her
You can't control her
You didn't cause her behavior
It is possible -essential- to keep our peace regardless of what others do, even if its our family. There are a few here that have learned to dettach from their own sons and daughters - how incredibly hard - but , you did your best, now her life is starting to be in her hands.... I really hope its just a stage and she is not an alcoholic..........
Anyway Alanon, therapy, reading and sharing here has helped me a lot. Among the books we like here there is "codependent no more" by Melody Beatty. And also "The Language of letting go" by the same author is excellent.